Page 65 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

APPENDIX B

Compiled Survey Responses

2. Please check the option that best describes your agency’s current retaining wall inventory.
Answer Choices	Responses	Percentage of Responses	Individual Responses
Answer Choices My DOT does not have a retaining wall inventory.	19	46.34%	AR, AZ, GA, HI, IA, ID, KY, MS, ND, NH, NJ, NM, NV, OK, SC, SD, TX, VA, WA
A complete inventory of all DOT-owned retaining walls.	5	12.20%	CO, KS, MD, PA, WI
A partial inventory (>50% of walls) that includes both bridge-associated walls and walls associated with other asset types (e.g. embankment or culvert-associated walls).	14	34.15%	AK, CA, CT, DE, FL, IL, IN, LA, MI, MN, NE, OH, OR, VT
A partial inventory (>50% of walls) that includes only bridge-associated walls.	0	0.00%
A partial inventory (<50% of walls) that includes both bridge-associated walls and walls associated with other asset types (e.g. embankment or culvert-associated walls).	3	7.32%	ME, TN, UT
A partial inventory (<50% of walls) that includes only retaining walls associated with bridges.	0	0.00%

3. Using the definition of an MSE wall provided at the beginning of the survey along with any minimum wall height requirements developed by your DOT, approximately how many MSE retaining walls is your agency responsible for? An estimate (+/- 10%) is acceptable if an inventory is not available.
Responses	Individual Responses
28	AK: 230, AR: 80, AZ: 100, CA: 848, CO: 630, CT: 31, DE: 40, FL: 1500, GA: 0, IA: 216, IN: 2500, KS: 307, KY: 50, LA: 450, ME: 80, MI: 49, MN: 165, NE: 285, NJ: 1200, OH: 900, OR: 444, PA: 528, SC: 600, TN: 500, TX: 100000, VT: 30, WA: 2000, WI: 785

Page 66 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

4. Regarding your previous answer, please select the most accurate statement.
Answer Choices	Responses	Percentage of Responses	Individual Responses
This is a count based on a thorough inventory.	7	21.88%	AR, CO, DE, IA, KS, OH, WI
This is an estimate based on the count from a partial inventory.	11	34.38%	AK, CA, CT, IN, LA, MI, MN, NE, OR, PA, VT
This is an experience-based estimate.	14	43.75%	AZ, FL, GA, IL, KY, ME, ND, NH, NJ, SC, TN, TX, UT, WA

5. Approximately what percentage of MSE walls owned by your DOT were designed using standards and codes that have since been superseded (e.g., Allowable Stress Design (ASD) vs. Load and Resistance Factor Design (LRFD), soil-reinforcement properties, seismic)? An estimate is acceptable.
Answer Choices	Responses	Percentage of Responses	Individual Responses
This is not tracked by our DOT.	24	66.67%	AK, AZ, CA, CO, CT, FL, IA, ID, IL, KY, MN, ND, NE, NH, NM, NV, OH, OR, PA, SC, TX, UT, VA, WA
0 - 20%.	4	11.11%	DE, MI, TN, VT
20 - 40%.	2	5.56%	AR, KS
40 - 60%.	4	11.11%	IN, LA, ME, WI
60 - 80%.	0	0.00%
> 80%.	2	5.56%	GA, NJ

6. MSE walls can be constructed with a wide range of facing and reinforcement types. If your DOT maintains a retaining wall inventory, how are MSE walls subdivided within the inventory? Please check as many as are applicable.
Answer Choices	Responses	Percentage of Responses	Individual Responses
Our DOT inventory collects only retaining wall type. There is no further subdivision of the MSE wall category based on facing or reinforcement.	12	38.71%	CA, DE, IA, IL, KY, MI, MN, ND, NE, PA, UT, VT
MSE type walls in my inventory are subdivided by facing type (e.g., geosynthetic wrapped face, precast panel, segmental block, welded wire).	9	29.03%	AK, CO, GA, KS, LA, ME, OH, OR, WI
MSE type walls in my inventory are subdivided by reinforcement type (e.g., geosynthetic grids, metallic straps, welded wire grids).	3	9.68%	AR, LA, OH
Other (please specify)	10	32.26%	AZ, CT, FL, IN, LA, NJ, SC, TN, TX, WA

Page 67 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

6. MSE walls can be constructed with a wide range of facing and reinforcement types. If your DOT maintains a retaining wall inventory, how are MSE walls subdivided within the inventory? Please check as many as are applicable.
Open Ended Answer	AZ: No inventory kept. CT: CTDOT categorizes MSE wall with metal reinforcement and precast concrete panel as MSE wall and the MSE wall with both metal reinforcement or geosynthetic reinforcement and concrete block as embankment wall. The embankment wall use is limited to the locations where wall height is less than 8 feet tall and the wall does not carry any traffic. FL: In our inventory, we don’t even differentiate between wall types (i.e., cantilever, MSE, gravity, soldier pile, etc.) IN: INDOT only uses precast concrete panels with steel reinforcement for permanent MSE Walls. Geogrids are typically used for Modular Block Walls over 5’ in height with no traffic loads. Welded wire facing is typically used for temporary MSE walls designed for 3 years or less. LA: A limited number of wall vendors with unique facings helps relate the type of reinforcement. For example, Reinforced Earth Company (RECO) has utilized/still utilizes a cruciform facing with associated metal strips. NJ: None SC: SCDOT doesn’t have an ERS inventory. TN: While TDOT does not have a full retaining wall inventory at this point. The Geotechnical Engineering Section does review all shop drawing submitted before approval to construct. However, MSE walls allowed on site are approved based on if the system is approved and up to date on the TDOT Qualified Products List (QPL38). The QPL is broke down into three facing types. Section B, 38.003 – MSE Wall (Segmental, Precast Facing) Section B, 38.004 – MSE Wall (Modular Block Facing) Section B, 38.008 – MSE Wall (other facing types) WA: We don’t have MSE wall inventory. TX: We do not have any retaining wall inventory at this time.

6. MSE walls can be constructed with a wide range of facing and reinforcement types. If your DOT maintains a retaining wall inventory, how are MSE walls subdivided within the inventory? Please check as many as are applicable.

Open Ended Answer

AZ: No inventory kept.

CT: CTDOT categorizes MSE wall with metal reinforcement and precast concrete panel as MSE wall and the MSE wall with both metal reinforcement or geosynthetic reinforcement and concrete block as embankment wall. The embankment wall use is limited to the locations where wall height is less than 8 feet tall and the wall does not carry any traffic.

FL: In our inventory, we don’t even differentiate between wall types (i.e., cantilever, MSE, gravity, soldier pile, etc.)

IN: INDOT only uses precast concrete panels with steel reinforcement for permanent MSE Walls. Geogrids are typically used for Modular Block Walls over 5’ in height with no traffic loads. Welded wire facing is typically used for temporary MSE walls designed for 3 years or less.

LA: A limited number of wall vendors with unique facings helps relate the type of reinforcement. For example, Reinforced Earth Company (RECO) has utilized/still utilizes a cruciform facing with associated metal strips.

NJ: None

SC: SCDOT doesn’t have an ERS inventory.

TN: While TDOT does not have a full retaining wall inventory at this point. The Geotechnical Engineering Section does review all shop drawing submitted before approval to construct. However, MSE walls allowed on site are approved based on if the system is approved and up to date on the TDOT Qualified Products List (QPL38). The QPL is broke down into three facing types.

Section B, 38.003 – MSE Wall (Segmental, Precast Facing)

Section B, 38.004 – MSE Wall (Modular Block Facing)

Section B, 38.008 – MSE Wall (other facing types)

WA: We don’t have MSE wall inventory.

TX: We do not have any retaining wall inventory at this time.

7. How long, in years, has your DOT had a specific program in place to manage some or all of its MSE wall assets outside of a bridge management system?
Answer Choices	Responses	Percentage of Responses	Individual Responses
0, no asset management program like this exists for MSE walls in my state.	21	58.33%	CA, DE, FL, GA, IA, ID, IL, KY, ND, NH, NJ, NM, NV, OK, PA, SC, TX, UT, VT, WA, WI
< 5 years.	5	13.89%	AR, KS, LA, MI, TN
5 - 10 years.	7	19.44%	AK, CO, IN, ME, MN, NE, OH
10 - 20 years.	2	5.56%	CT, OR
> 20 years.	1	2.78%	AZ

Page 68 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

8. Which group or groups within your DOT are responsible for inventorying and assessing MSE retaining walls? Please fill in the general percentage (0 to 100 scale, adding up to 100) that each group is responsible for. Percentages based on estimates are acceptable.
Answer Choices	Responses	Average Number	Individual Responses
Bridge.	16	54	CA: 95, CO: 100, DE: 100, IL: 10, IN: 50, KS: 10, LA: 5, ME: 20, MI: 75, MN: 50, OH: 10, OR: 15, PA: 100, TN: 20, VT: 100, WI: 98
Environmental.	1	1	CA: 1
Geotechnical/Geoengineering.	17	64	AZ: 100, CA: 2, CT: 100, GA: 100, IN: 50, KS: 90, LA: 5, ME: 30, MN: 20, ND: 100, NE: 100, NJ: 100, OH: 90, OR: 85, TN: 15, UT: 95, WI: 2
Maintenance and Operations.	7	51	AR: 100, IL: 90, KY: 100, LA: 5, ME: 50, MN: 10, UT: 5
Planning.	0
Roadway Design and Maintenance.	1	2	CA: 2
None, my DOT has no MSE wall asset management program.	12	94	AK: 100, FL: 100, IA: 100, ID: 100, LA: 65, NH: 100, NM: 100, NV: 100, SC: 100, TN: 65, TX: 100, WA: 100
Other (please specify in next question).	3	22	LA: 20, MI: 25, MN: 20

9. If you answered “Other” for the question above, please specify what other group is responsible for inventorying and assessing MSE retaining walls.
Open Ended Answer	CT: The geotechnical group is managing the retaining wall asset for CTDOT; however, the wall assessment is performed by the Department Consultants through the consultant bridge contract and the consultants performing the assessment do not necessarily have geotechnical background. LA: LTRC assisted with the initial collection of MSE Wall Assets, however Maintenance and Operations have yet to pull GAM in with the TAM operations. A second LTRC research is being developed to help fully integrate GAM. MI: Ancillary Structures Program area in the Bureau of Bridges MN: Asset Management NJ: Geotechnical Engineering is responsible for retaining walls. However, there is no inventory.

9. If you answered “Other” for the question above, please specify what other group is responsible for inventorying and assessing MSE retaining walls.

Open Ended Answer

CT: The geotechnical group is managing the retaining wall asset for CTDOT; however, the wall assessment is performed by the Department Consultants through the consultant bridge contract and the consultants performing the assessment do not necessarily have geotechnical background.
LA: LTRC assisted with the initial collection of MSE Wall Assets, however Maintenance and Operations have yet to pull GAM in with the TAM operations. A second LTRC research is being developed to help fully integrate GAM.
MI: Ancillary Structures Program area in the Bureau of Bridges
MN: Asset Management
NJ: Geotechnical Engineering is responsible for retaining walls. However, there is no inventory.

Page 69 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

10. Who collects data for your DOT’s MSE wall asset management program(s)?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Agency Staff.	9	26.47%	AR, IN, KS, ME, NE, OH, OR, UT, VT
Consultants.	2	5.88%	CO, GA
Both, depending on need and budget.	9	26.47%	AK, CT, DE, LA, MI, MN, PA, TN, WI
Not applicable.	14	41.18%	AZ, CA, FL, IA, ID, IL, KY, ND, NH, NJ, NM, SC, TX, WA

11. What types of distress does your DOT collect data on in MSE walls?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Deformation of facing.	16	45.71%	AR, CO, IN, KS, ME, MI, MN, NE, NV, OH, OR, PA, TN, UT, VT, WI
Pavement distress above wall.	11	31.43%	AK, CO, DE, IN, ME, MI, OR, PA, UT, VT, WI
Change in wall’s vertical or horizontal alignment.	14	40.00%	AK, CO, CT, DE, IN, KS, MI, MN, NE, NV, OR, PA, UT, WI
Degradation of wall foundation (e.g., scour, settlement).	13	37.14%	AK, CO, CT, IN, KS, ME, MI, MN, NE, OR, PA, UT, WI
Degradation of buried reinforcement.	2	5.71%	KS, NV
Damage to facing materials.	17	48.57%	AK, AR, CO, DE, IN, KS, ME, MI, MN, NE, OH, OR, PA, TN, UT, VT, WI
Damage or deformation of coping.	13	37.14%	CO, DE, IN, KS, ME, MI, MN, NE, OR, PA, UT, VT, WI
We do not collect any information on MSE wall distress.	13	37.14%	AZ, FL, IA, ID, IL, KY, LA, ND, NH, NJ, NM, SC, WA
Other (please specify).	10	28.57%	AR, CA, CT, GA, LA, MN, OR, TX, UT, VT

Page 70 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

11. Responses to “Other (please specify)”
Open Ended Answer	AR: Leaking Material and vegetation growth. CA: Distress of the roadway is tracked whether or not it comes from an MSE. We do not track MSE deformation directly. CT: The Department rated the condition of the retaining on a scale of 0-6 (where good is defined as 5 or 6, fair is defined as 3 or 4 and poor is defined as 0, 1 or 2). Out of the 24 walls that have been assessed only two were rated less than 6. The deficiencies noted are change of vertical alignment, minor loss of backfill and vegetation growth at the base of the wall. GA: We will collect all of the above, when we start our inventory. #3 required number, but it is unknown how many walls there are. LA: LTRC report 664 (https://www.ltrc.lsu.edu/pubs_final_reports.html#geo) helped identify inspection criteria templates, but these have yet to be enacted into full production. A web app was developed utilizing NCHRP report 903 on initial inventory condition and consequence status. MN: We don’t assess walls differently by wall type. Our inspection manual is based on wall elements (e.g. ERS Facing, Vertical Supports, Anchors, etc.) and material type (e.g. reinforced concrete, steel, timber, etc.) OR: Our asset management is performed by a single employee position, has been sporadic, and is currently on hold/not performed. Much of our database retaining walls are based as-constructed plans and only a fraction has had site visits and observations recorded. TX: We currently don’t collect MSE wall data. UT: The information selected above is evaluated, but only by our Geotechnical group when they are called to investigate an issue. VT: This isn’t specific to MSE walls, the bridge inspection group inspects all walls and bridge abutments/piers and applies the same inspection criteria to all.

11. Responses to “Other (please specify)”

Open Ended Answer

AR: Leaking Material and vegetation growth.

CA: Distress of the roadway is tracked whether or not it comes from an MSE. We do not track MSE deformation directly.

CT: The Department rated the condition of the retaining on a scale of 0-6 (where good is defined as 5 or 6, fair is defined as 3 or 4 and poor is defined as 0, 1 or 2). Out of the 24 walls that have been assessed only two were rated less than 6. The deficiencies noted are change of vertical alignment, minor loss of backfill and vegetation growth at the base of the wall.

GA: We will collect all of the above, when we start our inventory. #3 required number, but it is unknown how many walls there are.

LA: LTRC report 664 (https://www.ltrc.lsu.edu/pubs_final_reports.html#geo) helped identify inspection criteria templates, but these have yet to be enacted into full production. A web app was developed utilizing NCHRP report 903 on initial inventory condition and consequence status.

MN: We don’t assess walls differently by wall type. Our inspection manual is based on wall elements (e.g. ERS Facing, Vertical Supports, Anchors, etc.) and material type (e.g. reinforced concrete, steel, timber, etc.)

OR: Our asset management is performed by a single employee position, has been sporadic, and is currently on hold/not performed. Much of our database retaining walls are based as-constructed plans and only a fraction has had site visits and observations recorded.

TX: We currently don’t collect MSE wall data.

UT: The information selected above is evaluated, but only by our Geotechnical group when they are called to investigate an issue.

VT: This isn’t specific to MSE walls, the bridge inspection group inspects all walls and bridge abutments/piers and applies the same inspection criteria to all.

12. Has your DOT identified and implemented non-destructive testing methods for degradation of buried elements (i.e., steel coupons or geogrid)? If yes, please describe them in 1 to 2 sentences.
Answer Choices	Responses	Percentage of Responses	Individual Responses
No.	31	91.18%	AK, AR, AZ, CO, CT, DE, FL, GA, IA, ID, IL, IN, KY, LA, ME, MI, MN, ND, NE, NH, NJ, NM, OH, OR, PA, SC, TX, UT, VT, WA, WI
Yes, a description is provided below.	3	8.82%	CA, KS, NV

12. Has your DOT identified and implemented non-destructive testing methods for degradation of buried elements (i.e., steel coupons or geogrid)? If yes, please describe them in 1 to 2 sentences.
Open Ended Answer	CA: Steel inspection wires, sometimes called coupons, are placed along side steel soil reinforcement within the backfill. These were originally identified for pulling out after a specified number of years and returned to the laboratory for analysis. The original research program is no longer funded, so now the wires are pulled for analysis whenever a need arises. KS: We have used geogrid on several walls and coupons on a few others but it is not considered standard practice to include coupons. We have done this when the geomembrane was not installed correctly mainly. NV: coupons and exhume straps.

12. Has your DOT identified and implemented non-destructive testing methods for degradation of buried elements (i.e., steel coupons or geogrid)? If yes, please describe them in 1 to 2 sentences.

Open Ended Answer

CA: Steel inspection wires, sometimes called coupons, are placed along side steel soil reinforcement within the backfill. These were originally identified for pulling out after a specified number of years and returned to the laboratory for analysis. The original research program is no longer funded, so now the wires are pulled for analysis whenever a need arises.
KS: We have used geogrid on several walls and coupons on a few others but it is not considered standard practice to include coupons. We have done this when the geomembrane was not installed correctly mainly.
NV: coupons and exhume straps.

Page 71 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

13. What technologies does your DOT use to evaluate MSE wall condition and performance? Please check as many as are applicable.
Answer Choices	Responses	Percentage of Responses	Individual Responses
Ad hoc visual inspections during performance of other duties.	21	60.00%	AK, AR, CA, DE, GA, IL, IN, KS, LA, ME, MI, MN, ND, NE, NJ, OH, PA, TN, UT, VT, WI
Post-damage inspection when called out by field personnel.	19	54.29%	AK, CA, CO, DE, GA, IN, KS, LA, ME, MI, MN, NE, NJ, NV, OR, PA, TN, UT, WI
Repeat visual inspections and record-keeping.	19	54.29%	AK, CO, DE, GA, IN, KS, LA, ME, MI, MN, NE, NJ, NV, OH, PA, TN, UT, VT, WI
Repeat field survey completed by a surveyor.	7	20.00%	DE, GA, KS, LA, NJ, TN, UT
Change detection with remote sensing (e.g., LiDAR, InSAR, photogrammetry).	5	14.29%	AK, GA, LA, NJ, PA
Removal and testing of buried metal coupons or geogrid samples.	3	8.57%	CA, KS, NV
Other non-destructive testing of buried reinforcement materials.	3	8.57%	GA, KS, NV
Not applicable/None.	10	28.57%	AZ, FL, IA, ID, KY, NH, NM, SC, TX, WA
Other (please specify).	8	22.86%	AK, CT, GA, KS, LA, MN, OR, VT

13. Responses to “Other (please specify).”
Open Ended Answer	AK: Repeat visual inspections and other routine inspections are generally not performed unless damage or distress is recorded or observed during the performance of other duties. CT: Visual inspection is the primary method of retaining wall assessment at this time. The Department intends to initiate a routine assessment (2 years and 5 years frequency depending on the condition of the wall). The field personnel are tasked to notify the Department if they believe a more detailed assessment utilizing technologies such as 3D imagery is required. The Consultants are also tasked to notify the Department if a monitoring program besides the routine assessment is required. GA: All checked when we start. KS: We plan to start change detection soon. Our asset management program is still in its infancy. LA: Mostly reactive responses. For larger ongoing or more critical sites, repeated visual record keeping and surveys may apply. Change detection with lidar is being studied for implementation through an ongoing research project. MN: Though we haven’t done this yet, we plan to use remote sensing and photogrammetry in the near future. OR: When the program was funded, field visits to observe and record wall information was being done to collect the first round of information - not all walls had site visits. The site visits were being done in segments of highways; there is much remaining. VT: Ad-hoc by geotechnical team, routine by bridge inspection group

13. Responses to “Other (please specify).”

Open Ended Answer

AK: Repeat visual inspections and other routine inspections are generally not performed unless damage or distress is recorded or observed during the performance of other duties.

CT: Visual inspection is the primary method of retaining wall assessment at this time. The Department intends to initiate a routine assessment (2 years and 5 years frequency depending on the condition of the wall). The field personnel are tasked to notify the Department if they believe a more detailed assessment utilizing technologies such as 3D imagery is required. The Consultants are also tasked to notify the Department if a monitoring program besides the routine assessment is required.

GA: All checked when we start.

KS: We plan to start change detection soon. Our asset management program is still in its infancy.

LA: Mostly reactive responses. For larger ongoing or more critical sites, repeated visual record keeping and surveys may apply. Change detection with lidar is being studied for implementation through an ongoing research project.

MN: Though we haven’t done this yet, we plan to use remote sensing and photogrammetry in the near future.

OR: When the program was funded, field visits to observe and record wall information was being done to collect the first round of information - not all walls had site visits. The site visits were being done in segments of highways; there is much remaining.

VT: Ad-hoc by geotechnical team, routine by bridge inspection group

Page 72 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

14. Which data management tool does your DOT most rely on to compile information on MSE assets and share it with relevant parties as requested?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Central location for paper files.	3	9.38%	AZ, KY, ND
Electronic files on DOT server network.	5	15.63%	KS, NJ, PA, SC, UT
In-house database such as Oracle or Access.	5	15.63%	NE, OR, TN, VT, WI
In-house geodatabase, such as ESRI’s ArcMap.	3	9.38%	NH, CT, LA
Hosted cloud service, such as ESRI’s ArcGIS Online.	4	12.50%	AR, IN, ME, MI
Building Information Modeling (BIM) project files hosted in a shared data environment.	0	0.00%
Other (please specify)	12	37.50%	AK, CA, CO, DE, GA, IA, IL, MN, NM, OH, TX, WA

14. Responses to “Other (please specify).”
Open Ended Answer	AK: Both in-house geodatabase and hosted cloud services. CA: We have older paper files as well as an in house database for more recent as-built files. We are also now collecting GIS on the newest builds and experimenting with BIM. However, the majority of our MSE in service are in the database alone. CO: Consultant developed software and database DE: AASHTOWare BrM software GA: We are working on a research project with GA Tech, and will use ArcMap and Survey 123 IA: We only have a spreadsheet listing with no condition information. IL: N/A MN: We have an off the shelf asset management system developed by Agile Assets, and customized to meet our needs. NM: Data not collected. OH: ESRI ArcGIS Field Maps pushed to our Enterprise SQL Database. Hosted on public server for public (TIMS) TX: Don’t have a database. WA: No inventory to manage.

14. Responses to “Other (please specify).”

Open Ended Answer

AK: Both in-house geodatabase and hosted cloud services.

CA: We have older paper files as well as an in house database for more recent as-built files. We are also now collecting GIS on the newest builds and experimenting with BIM. However, the majority of our MSE in service are in the database alone.

CO: Consultant developed software and database

DE: AASHTOWare BrM software

GA: We are working on a research project with GA Tech, and will use ArcMap and Survey 123

IA: We only have a spreadsheet listing with no condition information.

IL: N/A

MN: We have an off the shelf asset management system developed by Agile Assets, and customized to meet our needs.

NM: Data not collected.

OH: ESRI ArcGIS Field Maps pushed to our Enterprise SQL Database. Hosted on public server for public (TIMS)

TX: Don’t have a database.

WA: No inventory to manage.

15. Does your DOT keep records of as-built conditions (designs, shop drawings, contract plans), specifically for use by the asset management program?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Yes.	18	52.94%	AZ, CO, CT, DE, IL, IN, KS, KY, ME, MI, MN, NE, NH, NJ, PA, UT, VT, WI
No.	16	47.06%	AK, AR, CA, FL, GA, IA, ID, LA, ND, NM, OH, OR, SC, TN, TX, WA

Page 73 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

16. How frequently does your DOT reinspect MSE walls?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Never.	8	22.86%	GA, IA, ID, KY, NH, NM, SC, WA
Only when tracking as a known problem.	9	25.71%	AZ, CA, LA, ND, NJ, NV, TN, TX, UT
Varies within the department based on wall location and which group is responsible for inventory and assessment (e.g., bridge-associated walls are inspected when the bridge is inspected).	7	20.00%	AK, AR, FL, IL, KS, ME, OR
Varies based on age of wall. An inspection interval based on wall age is set by my DOT.	0	0.00%
Every 1 to 5 years.	7	20.00%	CO, CT, DE, IN, MI, NE, PA
Every 5 to 10 years.	4	11.43%	MN, OH, VT, WI
Less frequently than every 10 years.	0	0.00%

17. Does your DOT have programmatic funding set aside for MSE wall maintenance or rehabilitation? If yes, please include the approximate percentage of the budget set aside annually for maintenance, preservation, or rehabilitation of MSE walls. Do not include costs for construction of new MSE walls or emergency repair of failed or damaged MSE walls.
Answer Choices	Responses	Percentage of Responses	Individual Responses
No.	32	91.43%	AK, AR, AZ, CA, DE, FL, GA, IA, ID, IL, KS, KY, LA, ME, MI, MN, ND, NE, NH, NJ, NV, OH, OR, PA, SC, TN, TX, UT, VT, WA, WI
Yes, the approximate percentage is:	3	8.57%	CO, CT, IN

17. Approximate percentages provided in previous question.
Open Ended Answer	CO: No set percentage for MSE walls, they are included in our entire retaining wall inventory, which is allocated approximately 0.9% of the overall Asset Management Funding CT: There is programmatic budget set aside for retaining wall, but the budget is not specific to a wall type. IN: 6 million/year

Page 74 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

18. Has your DOT implemented a program or developed guidance to replace or rehabilitate older MSE walls to align them with modern design guidance or construction standards, even if there is no evidence of distress or malfunction?
Answer Choices	Responses	Percentage of Responses	Individual Responses
No.	34	97.22%	AK, AR, AZ, CA, CO, CT, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, ME, MI, MN, ND, NE, NH, NJ, NM, NV, OR, PA, SC, TN, TX, UT, VT, WA, WI
Yes, and I am willing to provide a brief (2-3) sentence summary of that guidance or upload a copy of our guidance document.	1	2.78%	OH

19. Has your DOT implemented a program or developed guidance to replace MSE walls at the end of their calculated life span, even if the walls are not yet exhibiting distress or malfunction?
Answer Choices	Responses	Percentage of Responses	Individual Responses
No.	35	100.00%	AK, AR, AZ, CA, CO, CT, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, ME, MI, MN, ND, NE, NH, NJ, NM, NV, OH, OR, PA, SC, TN, TX, UT, VT, WA, WI
Yes, and I am willing to provide a brief (2-3) sentence summary of that guidance or upload a copy of our guidance document.	0	0.00%

Page 75 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

20. Referencing the definition of “proactive measure” provided at the beginning of this survey, what proactive measures has your DOT used outside of the MSE wall footprint to repair distressed walls or to rehabilitate MSE walls that do not meet current design or construction standards? Please fill in the general proportion of all proactive measures (0 to 100 scale, adding up to 100) represented by each selected measure. General percentages based on estimates (+/- 10%) are acceptable. If your DOT does not perform proactive measures, enter 100 into the box next to that option.
Answer Choices	Responses	Average Number	Individual Responses
Erosion/scour repair below wall.	12	28	AZ: 20, CO: 34, DE: 60, FL: 80, GA: 25, IN: 5, KS: 25, ME: 30, NE: 10, NJ: 20, PA: 20, WI: 33
Drainage improvements to direct water away from wall.	15	29	AZ: 20, CO: 33, DE: 10, FL: 20, GA: 40, IA: 10, IN: 35, KS: 50, ME: 30, MI: 50, NE: 10, NJ: 20, PA: 20, TN: 80, WI: 34
Removing material deposited by landslide or erosion above wall.	7	12	AZ: 20, DE: 10, ME: 20, NE: 10, NJ: 5, PA: 20, TN: 10
Removing fill placed above the wall following construction.	5	21	AZ: 20, CO: 33, GA: 35, NJ: 15, PA: 20
Repairing erosion damage above the wall.	11	30	AZ: 20, DE: 20, IA: 90, IN: 60, KS: 25, ME: 20, MI: 50, NE: 10, PA: 20, TN: 10, WI: 33
Our DOT does not perform proactive measures.	17	92	AK: 100, CA: 100, ID: 100, IL: 100, KY: 100, LA: 90, MN: 100, ND: 100, NE: 60, NH: 100, NM: 100, OH: 100, SC: 100, TX: 100, UT: 100, VT: 100, WA: 100
Other.	4	63	AR: 100, CT: 100, LA: 10, NJ: 40

Page 76 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

21. Of the proactive mitigation methods from the previous question, select the top three that have been most cost-effective for your DOT.
Answer Choices	Ranking	Responses	Percentage of Responses	Individual Responses
Erosion/scour repair below wall.	Most Effective	2	8.00%	AZ, FL
	Second Most Effective	4	19.05%	CO, DE, OR, PA
	Third Most Effective	5	26.32%	GA, IN, KS, TX, WI
Drainage improvements to direct water away from wall.	Most Effective	14	56.00%	CO, GA, IA, IN, KS, LA, ME, MI, NE, NJ, OR, PA, TN, WI
	Second Most Effective	3	14.29%	AZ, FL, TX
	Third Most Effective	1	5.26%	FL
Removing material deposited by landslide or erosion above wall.	Most Effective	1	4.00%	TX
	Second Most Effective	0	0.00%
	Third Most Effective	4	21.05%	DE, NE, OR, TN
Removing fill placed above the wall following construction. Repairing erosion damage above the wall.	Most Effective	0	0.00%
	Second Most Effective	1	4.76%	GA
	Third Most Effective	1	5.26%	NJ
	Most Effective	1	4.00%	DE
	Second Most Effective	9	42.86%	IA, IN, KS, ME, MI, NE, NJ, TN, WI
	Third Most Effective	3	15.79%	AZ, CO, PA
Our DOT does not perform proactive measures.	Most Effective	7	28.00%	AK, CA, ND, NH, NM, SC, WA
	Second Most Effective	4	19.05%	AK, LA, NM, WA
	Third Most Effective	5	26.32%	AK, IA, LA, NM, WA
Other.	Most Effective	0	0.00%
	Second Most Effective	0	0.00%
	Third Most Effective	0	0.00%

Page 77 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

22. Similar to the question above, what proactive measures has your DOT used within the MSE wall footprint to repair distressed walls or to rehabilitate MSE walls that do not meet current design or construction standards? Please fill in the general proportion of all proactive measures (0 to 100 scale, adding up to 100) represented by each selected measure. General percentages based on estimates (+/- 10%) are acceptable. If your DOT does not perform proactive measures, enter 100 into the box next to that option.
Answer Choices	Responses	Average Number	Individual Responses
Revegetation of wall face for wrapped facing.	3	17	AZ: 20, GA: 20, PA: 10
Removal of trees or large woody vegetation from wall face or at top of wall.	12	21	CO: 50, DE: 30, FL: 10, GA: 45, IN: 5, KS: 5, LA: 10, ME: 30, MI: 10, OH: 35, PA: 10, WI: 17
Repair of damaged/corroded/spalled concrete.	13	17	AZ: 20, CO: 25, FL: 10, IN: 10, KS: 5, LA: 10, ME: 20, MI: 25, NE: 10, OH: 35, PA: 10, TN: 30, WI: 17
Replacement of missing or damaged facing elements.	12	15	AZ: 20, CO: 24, FL: 10, GA: 10, IN: 5, KS: 5, MI: 20, NE: 20, OH: 10, PA: 10, TN: 30, WI: 17
Restoration of joint seals around displaced panels.	9	28	AZ: 20, DE: 30, GA: 10, IA: 100, IN: 35, MI: 20, MN: 10, PA: 10, WI: 17
Filling voids behind wall facing.	12	22	AZ: 20, DE: 20, FL: 50, GA: 10, IN: 25, KS: 25, ME: 30, MI: 20, NE: 10, OH: 10, PA: 10, TN: 30
Clearing drainage channels within wall.	6	23	GA: 5, IN: 5, LA: 10, ME: 20, MN: 90, PA: 10
Installation of additional drainage outlets into wall.	4	11	IN: 5, KS: 25, MI: 5, PA: 10
Installation of structural reinforcement (e.g., soil nails, soldier piles).	7	9	CO: 1, FL: 10, IN: 10, KS: 10, PA: 10, TN: 5, WI: 16
Treatment to prevent loss of backfill or damage to facing elements (e.g., shotcrete, grouting).	7	14	DE: 20, KS: 25, NE: 10, OH: 10, PA: 10, TN: 5, WI: 16
Encapsulate existing MSE wall in a new wall (MSE or other).	1	10	FL: 10
Our DOT does not perform proactive measures.	13	93	CA: 100, ID: 100, IL: 100, KY: 100, LA: 60, ND: 100, NE: 50, NH: 100, NJ: 100, SC: 100, TX: 100, UT: 100, WA: 100
Other.	3	70	AR: 100, CT: 100, LA: 10

Page 78 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

23. Of the proactive mitigation methods from Question 6, select the top three that have been most cost-effective for your DOT.
Answer Choices	Ranking	Responses	Percentage of Responses	Individual Responses
Revegetation of wall face for wrapped facing.	Most Effective	0	0.00%
	Second Most Effective	0	0.00%
	Third Most Effective	0	0.00%
Removal of trees or large woody vegetation from wall face or at top of wall.	Most Effective	6	23.08%	CO, DE, GA, ME, NJ, WI
	Second Most Effective	1	4.35%	OH
	Third Most Effective	0	0.00%
Repair of damaged/corroded/spalled concrete.	Most Effective	5	19.23%	LA, MI, OH, OR, TN
	Second Most Effective	2	8.70%	CO, WI
	Third Most Effective	1	4.55%	PA
Replacement of missing or damaged facing elements.	Most Effective	1	3.85%	NE
	Second Most Effective	1	4.35%	TN
	Third Most Effective	4	18.18%	CO, FL, GA, MI
Restoration of joint seals around displaced panels.	Most Effective	3	11.54%	IA, IN, PA
	Second Most Effective	1	4.35%	MN
	Third Most Effective	2	9.09%	DE, WI
Filling voids behind wall facing.	Most Effective	1	3.85%	FL
	Second Most Effective	6	26.09%	DE, IN, ME, MI, NJ, TX
	Third Most Effective	5	22.73%	AZ, NE, OH, OR, TN
Clearing drainage channels within wall.	Most Effective	2	7.69%	MN, TX
	Second Most Effective	3	13.04%	AZ, GA, PA
	Third Most Effective	2	9.09%	ME, NJ
Installation of additional drainage outlets into wall.	Most Effective	1	3.85%	KS
	Second Most Effective	0	0.00%
	Third Most Effective	0	0.00%
Installation of structural reinforcement (e.g., soil nails, soldier piles).	Most Effective	0	0.00%
	Second Most Effective	1	4.35%	KS
	Third Most Effective	1	4.55%	IN
Treatment to prevent loss of backfill or damage to facing elements (e.g., shotcrete, grouting).	Most Effective	1	3.85%	AZ
	Second Most Effective	2	8.70%	NE, OR
	Third Most Effective	2	9.09%	KS, TX
	Most Effective	0	0.00%
	Second Most Effective	1	4.35%	FL

Page 79 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

24. (Question 24 in the survey asked whether or not respondents wanted to continue with the last part of the survey.)
Encapsulate existing MSE wall in a new wall (MSE or other).	Third Most Effective	0	0.00%
Our DOT does not perform proactive measures.	Most Effective	6	23.08%	AK, ND, NH, NM, SC, WA
	Second Most Effective	4	17.39%	AK, IA, NM, WA
	Third Most Effective	5	22.73%	AK, IA, LA, NM, WA
Other.	Most Effective	0	0.00%
	Second Most Effective	1	4.35%	LA
	Third Most Effective	0	0.00%

25. How does your DOT define malfunction for MSE walls?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Deformation of facing.	9	90.00%	CO, IN, LA, ME, MI, MN, NE, OH, OR
Pavement distress above the wall.	6	60.00%	CO, IN, LA, ME, MI, OR
Change in wall alignment post-construction.	8	80.00%	CO, IN, LA, ME, MI, MN, NE, OR
Degradation of wall foundation (e.g., scour).	7	70.00%	CO, LA, ME, MI, MN, NE, OR
Degradation of buried reinforcement.	4	40.00%	CO, ME, MN, OR
Damage to facing materials.	9	90.00%	CO, IN, LA, ME, MI, MN, NE, OH, OR
Loss of backfill.	9	90.00%	CO, IN, LA, ME, MI, MN, NE, OH, OR
Other (please specify).	5	50.00%	CT, LA, ME, MN, OR

25. If you answered Other above, how does your DOT define malfunction for MSE walls?
Open Ended Answer	CT: CTDOT has not specified a malfunction for the MSE wall. We have tasked out consultants to assess the condition of the walls based on the general stability condition, backfill/infill and settlement condition and structural condition. The consultants are tasked to verify the condition of the facing panels and panel displacement, look for signs of backfill and/or infill loss, instability or distress behind the wall or any signs of settlement. LA: a combination of any of these two criteria could also occur. The amount of deformation, change, degradation, loss, etc. would likely need to be severe enough for district forces to notice. They may then request an inspection by HQ or LTRC for directions on how to proceed (is the asset functioning or malfunctioning?), and how to fix. ME: All of the listed problems would cause our Maintenance group to classify an MSE wall as malfunctioning. Some would trigger watching the wall, others would be more significant. MN: Please reach out to me for a copy of our retaining wall inspection manual. Again, we do not assess walls differently by wall type, but rather by wall elements and material type. OR: Our condition inspection manual is in progress and development, so draft only. All the listed observations would be noted in a site visit.

25. If you answered Other above, how does your DOT define malfunction for MSE walls?

Open Ended Answer

CT: CTDOT has not specified a malfunction for the MSE wall. We have tasked out consultants to assess the condition of the walls based on the general stability condition, backfill/infill and settlement condition and structural condition. The consultants are tasked to verify the condition of the facing panels and panel displacement, look for signs of backfill and/or infill loss, instability or distress behind the wall or any signs of settlement.

LA: a combination of any of these two criteria could also occur. The amount of deformation, change, degradation, loss, etc. would likely need to be severe enough for district forces to notice. They may then request an inspection by HQ or LTRC for directions on how to proceed (is the asset functioning or malfunctioning?), and how to fix.

ME: All of the listed problems would cause our Maintenance group to classify an MSE wall as malfunctioning. Some would trigger watching the wall, others would be more significant.

MN: Please reach out to me for a copy of our retaining wall inspection manual. Again, we do not assess walls differently by wall type, but rather by wall elements and material type.

OR: Our condition inspection manual is in progress and development, so draft only. All the listed observations would be noted in a site visit.

Page 80 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

26. How does your DOT define service failure for MSE walls?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Impact on traffic (e.g., shoulder closure, lane closure, slowdown).	9	90.00%	CO, CT, IN, LA, ME, MI, MN, NE, OR
Impact beyond DOT ROW.	6	60.00%	CO, LA, MI, MN, NE, OR
Excessive loss of retained material from behind the wall.	8	80.00%	CO, CT, IN, LA, MI, MN, NE, OR
Pavement distress/failure above the wall.	7	70.00%	CO, CT, IN, LA, ME, MN, NE, OH, OR
Other (please specify).	4	40.00%	LA, MN, OH, OR

26. If you answered Other above, how does your DOT define service failure for MSE walls?
Open Ended Answer	LA: As with the previous, the amount of impact (similar to NCHRP report 903) would likely contribute to the amount of risk. The NCHRP decision trees help gauge severity (and whether “failure or not”). MN: We don’t really have defined service failures, but all of these listed here would apply. OH: case by case basis. no specifics. OR: Our condition inspection manual is in progress and development, so draft only. All the listed observations would be noted in a site visit and represent loss of service function.

26. If you answered Other above, how does your DOT define service failure for MSE walls?

Open Ended Answer

LA: As with the previous, the amount of impact (similar to NCHRP report 903) would likely contribute to the amount of risk. The NCHRP decision trees help gauge severity (and whether “failure or not”).
MN: We don’t really have defined service failures, but all of these listed here would apply.
OH: case by case basis. no specifics.
OR: Our condition inspection manual is in progress and development, so draft only. All the listed observations would be noted in a site visit and represent loss of service function.

27. How does your DOT describe the condition of inventoried MSE wall assets?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Condition (100 to zero, Good/Fair/Poor).	7	70.00%	CO, CT, IN, MI, MN, NE, OH
Qualitative Risk (Low/Medium/High).	1	10.00%	LA
Qualitative Hazard (Low/Medium/High).	1	10.00%	ME
Quantitative Risk (Percent likelihood of failure, estimated incurred costs, or similar).	0	0.00%
Numerical score (similar to Rockfall Hazard Rating System or Unstable Slopes Management Program scoring).	1	10.00%	OR

Page 81 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

28. What factors or inspection items does your department use when determining the condition of an MSE wall? Please check all that are used by your department. If different criteria are used by different groups, please explain in the comments at the end of this question.
Answer Choices	Responses	Percentage of Responses	Individual Responses
Changes in vertical or horizontal alignment since construction.	9	90.00%	CO, CT, IN, LA, ME, MI, MN, NE, OR
Settlement behind wall.	8	80.00%	CO, CT, IN, LA, ME, MI, NE, OR
Functionality of drainage features.	9	90.00%	CO, IN, LA, ME, MI, MN, NE, OH, OR
Damage to facing elements (corrosion, cracking, tearing, etc.)	10	100.00%	CO, CT, IN, LA, ME, MI, MN, NE, OH, OR
Testing of buried materials for internal corrosion or degradation.	1	10.00%	LA
Distress in ground or pavement below wall.	7	70.00%	CO, CT, IN, LA, ME, MI, OR
Distress in ground or pavement on either side of wall.	6	60.00%	CO, CT, LA, ME, MI, OR
Loss of retained material from behind the wall.	10	100.00%	CO, CT, IN, LA, ME, MI, MN, NE, OH, OR
Change in alignment and spacing of facing panels and joints since construction.	10	100.00%	CO, CT, IN, LA, ME, MI, MN, NE, OH, OR
Vegetation growth on wall face or within panel joints.	8	80.00%	CO, CT, IN, LA, MN, NE, OH, OR
Criteria for wall condition varies based on the group within the DOT performing the inspection (e.g., Bridge versus Geotechnical). If this option is selected, please briefly specify the differences.	1	10.00%	CO, CT, IN, LA, ME, MI, MN, NE, OH, OR

28. If you answered Other above, how does criteria for wall condition vary based on the group within the DOT performing the inspection (e.g., Bridge versus Geotechnical).
Open Ended Answer	LA: Some walls are more closely associate with bridge elements and receive attention from Bridge Maintenance. In contrast, District forces may notice criteria and request HQ-Geotechnical to assist and conduct a more detailed inspection. Reactive actions by Districts are common, however, proactive efforts are still being realized.

29. Which method does your DOT use to rank MSE walls to prioritize budget spending?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Consequence of failure.	0	0.00%
Likelihood of failure.	1	10.00%	ME
Overall condition.	3	30.00%	CO, IN, NE
Risk to users.	0	0.00%
No prioritization method exists.	3	30.00%	MI, OH, OR
Other (please specify).	3	30.00%	CT, LA, MN

Page 82 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

29. If you answered Other above, which method does your DOT use to rank MSE walls to prioritize budget spending?
Open Ended Answer	CT: We prioritize the walls for project initiation based on the overall condition and risk analysis (combination of likelihood of failure and consequence of failure); however, this is applicable to all wall types not MSE walls only. LA: The LTRC report 664 (based on NCHRP 903) outlines a strategy based on Condition and Consequences that was recommended to DOTD, awaiting implementation. MN: We prioritize based on both condition and risk (a function of consequence and likelihood)

29. If you answered Other above, which method does your DOT use to rank MSE walls to prioritize budget spending?

Open Ended Answer

CT: We prioritize the walls for project initiation based on the overall condition and risk analysis (combination of likelihood of failure and consequence of failure); however, this is applicable to all wall types not MSE walls only.
LA: The LTRC report 664 (based on NCHRP 903) outlines a strategy based on Condition and Consequences that was recommended to DOTD, awaiting implementation.
MN: We prioritize based on both condition and risk (a function of consequence and likelihood)

30. Decision support tools can range from a formal department document to an informal set of institutional norms. Which of the following options best describes your DOT’s decision support tools for managing MSE wall assets?
Answer Choices	Responses	Percentage of Responses	Individual Responses
We have a formal decision support document that we reference when prioritizing work on existing MSE wall assets.	0	0.00%
We have an informal set of guidelines that we are in the process of codifying into a formal decision support tool.	4	40.00%	CT, IN, LA, MN
We have informal decision support tools based on institutional knowledge and past experience.	4	50.00%	CO, ME, MN, OH
We have no decision support guidance of any kind.	1	10.00%	OR

31. What type of criteria does your DOT use in your decision support tools (whether formal or informal) to prioritize rehabilitation or repair of existing MSE walls?
Answer Choices	Responses	Percentage of Responses	Individual Responses
Benefit/cost analyses.	0	0.00%
Combination of roadway functional classification and target wall condition.	2	20.00%	CO, LA
Impact of failure.	1	10.00%	ME
Risk-based selection process.	3	30.00%	CT, MI, MN
Target wall condition.	2	20.00%	IN, NE
None of the above.	2	20.00%	OH, OR

Page 83 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

32. Does your DOT track ownership costs associated with retaining walls? Please check all that apply.
Answer Choices	Responses	Percentage of Responses	Individual Responses
We track construction cost (i.e., bid tabulations).	6	60.00%	CT, LA, ME, MI, OH, OR
We track repair costs by wall type (either through external damage or via deterioration).	1	10.00%	CT
We track rehabilitation costs by wall type (e.g., installation of improved drainage features).	0	0.00%
We track inspection costs (either in-house or contracted).	3	30.00%	CO, MI, MN
We track maintenance costs by wall type (drain cleaning, coatings, vegetation clearing, etc.).	1	10.00%	MN
None of the above are tracked by our DOT for retaining wall assets.	2	20.00%	IN, NE

33. Long-term deterioration of MSE walls can be factored into the design and construction of new MSE wall assets. Please check any of the following options that describe how your DOT has factored long-term deterioration of MSE walls into current design and construction.
Answer Choices	Responses	Percentage of Responses	Individual Responses
Incorporate lessons learned from failures to increase the design life of new walls.	5	50.00%	CO, IN, MI, MN, NE
Incorporate lessons learned from long-term deterioration to update construction methods.	5	50.00%	CO, IN, MI, MN, NE
Improved cost-benefit analysis for project prioritization.	0	0.00%
Develop agency benefit factors to help prioritize current mitigation projects.	1	10.00%	NE
We do not currently have a method to factor long-term deterioration into current design and construction.	4	40.00%	CT, LA, ME, OH
Other (please specify).	1	10.00%	OR

33. If you answered Other above, please describe how your DOT has factored long-term deterioration of MSE walls into current design and construction.
Open Ended Answer	OR: We follow design life criteria, use AASHTO LRFD corrosion loss estimate, consider environment of wall (exposure to deicing chemicals, coastal areas, extreme conditions).

Page 84 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

34. Development of life cycle costs is an important component of a fully implemented asset management program. Please select the option that best describes the work your DOT has completed to date on developing life cycle costs for MSE wall assets.
Answer Choices	Responses	Percentage of Responses	Individual Responses
We have developed different life cycle costs for different types of MSE walls based on facing and reinforcement types.	0	0.00%
We have developed an overall life-cycle cost for an MSE wall asset.	0	0.00%
We have developed a life-cycle cost for a generic retaining wall asset.	1	10.00%	MN
We have not yet collected sufficient data to complete such an analysis.	9	90.00%	CO, CT, IN, LA, ME, MI, NE, OH, OR

Page 85 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.

Abbreviations and acronyms used without definitions in TRB publications:

A4A	Airlines for America
AAAE	American Association of Airport Executives
AASHO	American Association of State Highway Officials
AASHTO	American Association of State Highway and Transportation Officials
ACI–NA	Airports Council International–North America
ACRP	Airport Cooperative Research Program
ADA	Americans with Disabilities Act
APTA	American Public Transportation Association
ASCE	American Society of Civil Engineers
ASME	American Society of Mechanical Engineers
ASTM	American Society for Testing and Materials
ATA	American Trucking Associations
CTAA	Community Transportation Association of America
CTBSSP	Commercial Truck and Bus Safety Synthesis Program
DHS	Department of Homeland Security
DOE	Department of Energy
EPA	Environmental Protection Agency
FAA	Federal Aviation Administration
FAST	Fixing America’s Surface Transportation Act (2015)
FHWA	Federal Highway Administration
FMCSA	Federal Motor Carrier Safety Administration
FRA	Federal Railroad Administration
FTA	Federal Transit Administration
GHSA	Governors Highway Safety Association
HMCRP	Hazardous Materials Cooperative Research Program
IEEE	Institute of Electrical and Electronics Engineers
ISTEA	Intermodal Surface Transportation Efficiency Act of 1991
ITE	Institute of Transportation Engineers
MAP-21	Moving Ahead for Progress in the 21st Century Act (2012)
NASA	National Aeronautics and Space Administration
NASAO	National Association of State Aviation Officials
NCFRP	National Cooperative Freight Research Program
NCHRP	National Cooperative Highway Research Program
NHTSA	National Highway Traffic Safety Administration
NTSB	National Transportation Safety Board
PHMSA	Pipeline and Hazardous Materials Safety Administration
RITA	Research and Innovative Technology Administration
SAE	Society of Automotive Engineers
SAFETEA-LU	Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005)
TCRP	Transit Cooperative Research Program
TEA-21	Transportation Equity Act for the 21st Century (1998)
TRB	Transportation Research Board
TSA	Transportation Security Administration
U.S. DOT	United States Department of Transportation

Page 86 Bookmark

Suggested Citation: "Appendix B: Compiled Survey Responses." National Academies of Sciences, Engineering, and Medicine. 2025. Asset Management Practices for Mechanically Stabilized Earth Walls. Washington, DC: The National Academies Press. doi: 10.17226/29115.