Active Design Memos
Updated 2/9/26
The design memos are generally published during the second week of each month. Unless stated otherwise, any revisions to the Indiana Design Manual (IDM) will be published at the same time.
Memos remain active for one year before being moved to the Archived Design Memos page. Superseded memos are archived immediately. Memos that contain guidance not yet included in the IDM or other INDOT publications may remain active for a longer period. Additionally, memos that are integral to applying a recurring special provision (RSP) or recurring plan detail (RPD) may also be kept active longer.
The practice of distinguishing between policy memos and technical advisories was discontinued in January 2018.
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 26-06 | 2/9/26 | Law Enforcement Officer RSP | Fig. 14-1C | Lettings on or after May 1, 2026 |
| 26-05 | 2/9/26 | Prestressed Beam Imposed Deformations | 406-12.06 | Stage 3 on or after March 1, 2026 |
| 26-04 | 2/9/26 | Prestressed Beam Camber and Fillet Loads | 406-12.04(03), Fig. 406-12E[New], Fig. 406-12F[New] |
Stage 3 on or after March 1, 2026 |
| 26-03 | 1/14/26 | Pipe Backfill Calculator (Updated Program) | 17-3.02, 17-3.03, Fig. 17-3A |
Immediately |
| 26-02 | 1/14/26 | Mobilization and Demobiliation for Seeding | N/A | N/A |
| 26-01 | 1/14/26 | Post-Construction Stormwater Management | N/A | As Noted |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 25-22 | 12/10/25 | Special Partial Coating System | Fig. 17-5L | Lettings on or after June 1, 2026 |
| 25-21 | 12/10/25 | Plastic Pipe Material Types Attachments: Pipe Material Table XLS Pipe Material Table PDF Pipe Material Table DGN |
N/A | Lettings on or after June 1, 2026 |
| 25-20 | 12/10/25 | Construction Signs | N/A | Lettings on or after March 1, 2026 |
| 25-19 | 9/10/25 | Traffic Signal Preemption and Light Trespass | 502-3.03(03), 502-4.06(03) | Lettings on or after December 1, 2025 |
| 25-18 | 8/13/25 | Update to IHCP Templates | N/A | Immediately |
| 25-17 | 8/13/25 | Permanent Seeding Fertilizer Rate | 17-4.10(01), 17-4.10(03) | Lettings on or after December 1, 2025 |
| 25-16 | 8/13/25 | Pavement Type Selection Process | 601-5.01(03), 602-2.0, 606-1.0 | Immediately |
| 25-15 | 7/15/25 | Bridge Deck Overlay | 17-5.12[New], 412-3.02, Fig. 17-5M[New], Fig. 412-3C |
Lettings on or after September 1, 2025 |
| 25-14 | 5/7/25 | CAD Workspace Updates | N/A | Stage 3 on or after June 1, 2025 |
| 25-13 | 5/7/25 | 2025 INDOT Standard Drawings | N/A | Lettings on or after September 1, 2025 |
| 25-12 Rev. | 4/16/25 rev. 5/7/25 |
Plan Revisions after Ready for Contracts | 14‐1.02(04), 14‐1.02(06), 14‐1.02(07), Fig. 14‐1O[New], Fig. 14‐1P[New], Fig. 14‐1Q[New] |
Immediately |
| 25-11 | 4/16/25 | Lean Concrete Base | 17‐5.09(02), 603‐3.01, 604‐2.03 | Lettings on or after June 1, 2025 |
| 25-10 | 4/16/25 | Void Reducing Asphalt Membrane for Asphalt Paving | 602‐3.02 | Lettings on or after September 1, 2025 |
| 25-09 | 4/16/25 | Rewrite Chapter 43 Horizontal Alignment | Chapter 43 (all sections), 48‐4.01(06), 48‐5.03(01), 48‐5.03(02) |
Stage 2 on or after July 1, 2025 |
| 25-08 | 3/25/25 | Life-Cycle Pavement Cost Analysis Update | 602-2.0, 606-1.0, 606-2.05, 606-3.01, 606-3.02 |
Lettings on or after September 1, 2025 |
| 25-07 | 2/13/25 | Topsoil Management | 17-4.10, 17-4.10(01), 17-4.10(02), 17-4.10(03), 17-4.10(09)[New] |
Lettings on or after September 1, 2025 |
| 25-06 | 2/13/25 | Prestressing Strands | 406-10.0, 406-12.02(03) | Lettings on or after September 1, 2025 |
| 25-05 | 2/13/25 | Reinforcing Bar Support Devices | 406-12.03(03), Fig. 405-3D, Fig. 405-3E, Fig. 406-12D[New] |
Lettings on or after September 1, 2025 |
| 25-04 | 2/13/25 | NEXT Beams | 406-12.02(01), Fig. 406-14BB, Fig. 406-14DD |
Lettings on or after September 1, 2025 |
| 25-03 | 1/21/25 | Maintenance of Traffic Updates | 503-2.05(01), 503-6.01, 503-7.01(04), 503-7.03, 503-7.05 |
Lettings on or after September 1, 2025 |
| 25-02 | 1/21/25 | Various Traffic Design Updates | 502-1.01(06), 502-1.01(14), 502-1.02(09)[New], 502-3.06(07)[New], 502-4.03(05), 502-4.07, Fig. 502-1E |
Lettings on or after September 1, 2025 |
| 25-01 | 1/21/25 | IHCP Exception Requests | N/A | As Noted |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 24-17 | 12/4/24 | Liquid Asphalt Sealant | Figs. 602‐3A thru 602-3D, 602-3G, 602-3H, 602-3J | Immediately |
| 24-16 | 11/6/24 | MSE Wall Shop Drawing Review Checklist | N/A | Immediately |
| 24-15 | 11/6/24 | FHWA-Indiana PS&E Checklist | 14-2.01(13), 14-2.03(10), 14-2.04(09), 14-2.05(05), 14-2.06(03), 14-2.07(03), 14-2.08(03) |
Lettings on or after September 1, 2025 |
| 24-10 | 8/14/24 | Pavement Patching Tables | N/A | As Noted |
| 24-08 | 6/19/24 | MOT on High-Volume Interstate Highways | N/A | Immediately |
| 24-06 | 4/11/24 | IHCP Contract Documents | N/A | As noted |
| 24-05 | 4/11/24 | PROWAG Elements Phased Implementation | N/A | Lettings on or after July 1, 2028 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 23-21 | 12/8/23 | HMA Pavement PG Binder | 601-2.0, 601-3.0, 601-5.01(04), Fig. 601-5C 602-3.02, 602-3.02(01) thru 3.02(03) 607-1.0, 607-1.01 |
Lettings on or after September 1, 2024 |
| 23-17 | 10/16/23 | Placing and Terminating Temporary Traffic Barrier | N/A | Lettings on or after December 1, 2023 |
| 23-16 | 10/16/23 | Public Rights-of-Way Accessibility Guidelines (PROWAG) | N/A | Lettings on or after July 1, 2024 |
| 23-10 | 8/14/23 | Bridge Painting | 17-5.11 | As Noted |
| 23-08 | 7/11/23 | Railroad Flagging | 105-3.03 | Lettings on or after January 1, 2024 |
| 23-07 | 7/11/23 | Guardrail End Treatments | N/A | Lettings on or after October 1, 2023 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 22-22 | 11/10/22 | Post-construction Stormwater Management | IDM Chapter 204 | As Noted |
| 22-17 | 9/13/22 | AASHTO LRFD Bridge Design Specifications | N/A | Stage 2 on or after March 1, 2023 |
| 22-05 | 4/20/22 | Concrete Median Barrier for Interstate Routes | N/A | Immediately |
| 22-01 | 1/6/22 | Stage 2 Documents for Publication | 14-2.01(07), 14-2.04(06), 14-2.05(03), 14-2.06(02), 14-2.07(02), 14-2.08(02) |
Stage 2 on or after January 6, 2022 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 21-18 Rev. | 9/9/21 rev. 2/09/22 rev. 7/11/23 |
Scour Requirements for Bridge Preventive Maintenance Projects | 14-2.05, 412-2.0, Fig. 412-2C[Rev] | Stage 1 on or after October 1, 2021 |
| 21-04 | 3/11/21 | Full Depth Reclamation (FDR) Projects and Rule 5 Permits | N/A | Immediately |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 20-14 | 8/6/20 | Preventative Maintenance and 3R Design Criteria for Freeway and Interstate Resurfacing Projects Attachment: August 2020 Q&A for Design Memos 20-13 & 20-14 |
N/A | Immediately |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 18-26 | 11/8/18 | Pedestrian Pushbutton and ADA Plan Details | 51-1.06(03) | Stage 3 on or after March 1, 2019 |
| 18-20 | 8/6/18 | Bridge Aesthetics Policy | N/A | Immediately |
| 18-05 | 3/5/18 | Plan Note for TAC Approved ADA Inquiries | N/A | Stage 3 on or after April 2, 2018 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 17-20 | 9/5/17 | Complex Bridge Design Requirements | N/A | Immediately |
| 17-17 | 8/7/17 | Manual for Assessing Safety Hardware (MASH) and New W-beam Guardrail and Guardrail End Treatment Standards Attachment: Pay Items Associated with MGS W-Beam Guardrail and Related Systems |
N/A | NHS Routes: Letting on or after January 1, 2018, Non-NHS Routes: Letting on or after July 1, 2018 |
| 17-10 | 5/11/17 | Manual for Assessing Safety Hardware (MASH) and New W-beam Guardrail and Guardrail End Treatment Standards Attachment 1: Midwest Guardrail System Assembly Figures Attachment 2: AASHTO/FHWA Joint Implementation Agreement for MASH Memo |
N/A | NHS Routes: Letting on or after January 1, 2018, Non-NHS Routes: Letting on or after July 1, 2018 |
| 17-04 Rev. | 3/16/17 Rev. 11/13/17 | Culvert Asset ID Number Attachment: Culvert Asset ID Numbering System |
N/A | Stage 3 on or after May 2017 |
| 17-02 | 2/2/17 | Rural Interstate Shoulder Width | N/A | Immediately |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 16-35 | 11/21/16 | Undistributed Quantities | N/A | Immediately |
| 16-10 | 3/16/16 | NEPA Compliance and Waterway Permitting for Bundled Projects Attachment: INDOT Environmental Memo |
N/A | Immediately |
| 16-01 | 1/5/16 | Structure Number in ERMS, SPMS, and on Plans Attachment: Example |
N/A | Immediately |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 13-09 | 4/12/13 | Small Structure Replacement, Guardrail Runout Length Attachment: RDG Table 5-10(b) |
Chapters 49 & 55 | Preliminary Field Check on or after June 1, 2013 and as noted |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 11-09 | 4/5/11 | High-Tension Cable-Barrier System (CBS) Attachment: RSP 627-R-546 Attachment: RPD 627-R-546d |
49-5.01(04) | Lettings on or after May 11, 2011 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 05-34 | 11/9/05 | Concrete Railings & Moment Slabs at Mechanically Stabilized Earth (MSE) Wall Systems Attachment: 706-R-504 RSP & RPD |
49-4.01(05) | February 15, 2010 |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 03-07 | 7/2/03 | Policy for Context Sensitive Solution | N/A | Immediately |
| Memo Number | Memo Date | Subject | Affected IDM Section, Figure, or Reference | Effective Date |
| 01-14 | 12/10/01 | Water Main & Sanitary Sewer Construction in Contracts | N/A | Immediately |