AASHTO Subcommittee on Design Reducing Engineering Standards: Good or Bad?

1. AASHTO Subcommittee on Design Reducing Engineering Standards: Good or Bad? July 14, 2008 Marc Cote, P.E. (302) 760-2266 E-Mail: marc.cote@state.de.us AASHTO Subcommittee on Design

2. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design Delaware is probably somewhat unique in that 91% of the roads in Delaware are state maintained. Access to individual homes and streets in small subdivisions all have to be approved by my office in addition to the large subdivisions and commercial developments.

3. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design

4. Reducing Engineering Standards: Good or Bad? 7/14/08 AASHTO Subcommittee on Design Subdivision Manual requires that subdivisions generating more than 400 vpd or 50 vph in the peak hour conduct a traffic impact study. In addition to offsite improvements outlined in the TIS, the developer is required to improve his road frontage to meet the standards for the functional classification of the road.

5. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design

6. Reducing Engineering Standards: Good or Bad? • A completed design checklist must be filled out noting that all of the required information has been included on the plans, the design criteria is met, and is in accordance with DelDOT’s Standard Construction Details and Standards and Specifications. • Preliminary entrance plans shall include but are not limited to the following: traffic generation diagram, adjacent entrances, functional classification of adjacent roadway, layout of required auxiliary lanes, sight distance calculations. AASHTO Subcommittee on Design

7. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design Developers are making substantial improvements to our road system and there are factors to consider: Right of way impacts – local opposition Cost of improvements vs. the cost of housing Improved roads over existing conditions If improvements are too extensive, development doesn’t happen, improvement doesn’t happen Support for economic development if it is planned

8. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design Want the best product for our citizens at the best cost Need solution that works, doesn’t have to be the perfect solution Improve the existing condition Don’t compromise on safety

9. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design Thomas Jefferson once said that: “The first obligation of government is to provide for the safety of the people.”

10. Reducing Engineering Standards: Good or Bad? Areas for consideration • Design speed • Lane width • Shoulder width • Stopping sight distance on vertical and horizontal curves • Vertical alignment • Minimum and maximum grades • Cross slopes • Superelevation rate • Horizontal clearance • Vertical clearance • Bridge width • Structural capacity AASHTO Subcommittee on Design

11. Reducing Engineering Standards: Good or Bad? Standards to be maintained: • Design speed • Stopping sight distance on vertical and horizontal curves • Vertical alignment • Minimum and maximum grades • Vertical clearance • Bridge width • Structural capacity • Lane width • Standards considered for reduction: • Shoulder width • Cross slopes • Superelevation rate • Horizontal clearance • Bridge width AASHTO Subcommittee on Design

12. Reducing Engineering Standards: Good or Bad? • Development Related Improvements Requiring New Rights-of-Way Gives DelDOT ability to acquire right-of-way for projects done by others (developers) to make improvements for the public’s benefit in the interest of safety. AASHTO Subcommittee on Design

13. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design

14. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design

15. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design

16. Background: International Fire Code (IFC) states “fire access road shall have an unobstructed width of at least 20 feet.” DelDOT Standards and Regulations for Subdivision Streets and Highway Access Issue: “Are existing 22’ wide streets too narrow to accommodate emergency vehicles?” “Should a 24’ section be adopted by DelDOT?”

17. Wide Streets • Can encourage speeding • Increase impervious area • May reduce the livability of a residential street • Undermine perceived pedestrian/cyclist safety • Inconsistent with residential traffic patterns • Higher maintenance costs • Community requests for traffic calming measures “Encourages High Speeds” • Narrow Streets • May inhibit emergency response • Can constrain snow plowing operations • May discourage free flowing traffic • Reduce vehicular speed • Can improve pedestrian and cyclist safety • Reduce maintenance • Less impervious area “What Fire Departments Fear” Source: Arlington County, VA residential streets presentation

18. Subdivision Street Type 1-With Curb (Emergency Vehicle and Standard Vehicle) Sidewalk 5’ Grass Strip 3’ Curb 2’ Gutter Pan 11” Fire Engine 9.5’ (mirror to mirror) Lane 11’ Pickup Truck 6.6’ Lane 11’ Gutter Pan 11” Curb 2’ Grass Strip 3’ Sidewalk 5’ Existing DelDOT Standards Graphics by DelDOT Division of Planning Source: DelDOT Standards and Regulations for Subdivision Streets and State Highway Access

19. Subdivision Street Type 1-With Curb w/ 11’ Lanes (Emergency Vehicle and Standard Vehicle) Subdivision Street Type 1-With Curb w/ 12’ Lanes (Emergency Vehicle and Standard Vehicle) Top View Top View Top View Proposed DelDOT Standards w/parking both sides of street Existing DelDOT Standards w/parking both sides of street Graphics by DelDOT Division of Planning

20. Subdivision Street Type 1-With Curb w/ 11’ Lanes (Emergency Vehicle and Standard Vehicle) Subdivision Street Type 1-With Curb w/ 12’ Lanes (Emergency Vehicle and Standard Vehicle) Proposed DelDOT Standards w/parking both sides of street Front View Front View Existing DelDOT Standards w/parking both sides of street Graphics by DelDOT Division of Planning

21. Conclusion: The adoption of new 12’ lane requirements for subdivision streets that fall under the guidelines of the DelDOT Standards and Regulations for Subdivision Streets and Highway Access would enhance the ability of emergency vehicles to safely reach their intended destinations Sidewalk 5’ Grass Strip 3’ Curb 2’ Gutter Pan 11” Lane 12’ Lane 12’ Gutter Pan 11” Curb 2’ Grass Strip 3’ Sidewalk 5’ Proposed DelDOT Standards Graphics by DelDOT Division of Planning

22. Reducing Engineering Standards: Good or Bad? AASHTO Subcommittee on Design