1. TRENDS AND HIGHWAY CLASSIFICATIONS
Spring 2017

2. Examples of highway design problems

3. Examples of highway design problems

4. Examples of highway design problems

5. Examples of highway design problems

6. Examples of highway design problems

7. Important Issues in Highway Design
Automobile Oriented Society
More cars than drivers (BTS Survey 03)
Shift from construction of new facilities to maintenance of existing facilities (e.g., lane widening, paving, intelligent transportation systems, etc.)
Resurgence in highway funding
Concern for conditions of infrastructure
Renewed public willingness for public expenditures (e.g., current bill in Texas to increase funding for highways)
Reauthorization of transportation funds ($286.5B)

8. I-35W Bridge Collapse

9. Important Issues in Highway Design
Fleet of vehicles
Larger trucks/smaller vehicles
Better vehicles performance and design (e.g., lower center of gravity, improved acceleration, lighter vehicle components, etc.)
Age of population
Baby boomers are getting older (20% 65+ in 2003)
Safety issues with older (i.e., visual search, reaction time, more fragile health, etc.)

10. Important Issues in Highway Design
Value Engineering
New area that aims to find ways to save money in design
Has been applied in highway design
Can compromise safety (e.g., Highway 407 in Ontario, Canada)
Liability
Increasing number of lawsuits (DOTs, Cities, MPOs, etc.)
Usually always based on (un)safety (after crashes occur)

11. Important Issues in Design
Safety Audits
Becoming increasingly popular (liability is a factor)
Explicitly look at all safety components of a project (from initial concept to construction)
Goes beyond design guidelines
New design criteria under development
Less focused on vehicle speed
Sensitive context design
Transportation Security
Terrorist threats against transportation infrastructures
See, e.g.,

12. The Design Objective
A well-designed road will provide the intended level of service, at an acceptable cost, with an acceptable level of safety. It will also reflect local values and policy, which will vary from location to location. If it has been designed with care and sound judgment, it will place appropriate importance on safety, cost, service, environmental values, and appearance.

13. Goals of Highway Design
Traffic Quality
Economy
Aesthetics
Function (to be discussed later)
Traffic Safety
Environmental protection

14. Road Network Design
The road network is part of the overall traffic infrastructure (railway, waterway, communication, etc.).
It is the essential element in developing rural and urban areas.
Consequently, the road network design influences the spatial development as well as the local space structure.
The task of network design should be to arrange and design the individual road sections according to their respective functions within the scope of transportation and regional planning

15. Role of Highways Two primary roles of Highway and Street Networks are:
Travel Mobility: To provide users with means to travel from a point of origin to a point of destination the most efficient and safest way possible
Access: To provide users access to services and property the most efficient way possible

16. Mobility

17. Access

18. Wright and Dixon (2004) Figure 1-2

19. Functional Classification
Based on Design Types eg. Freeways, Conventional Streets and highways
Based on route numbering
eg. U.S., State, County
Based on Administrative System
eg. National and Non-National Highways
Functional Classification

20. Urban/Rural Areas Urban and rural differ with regard to
Density
types of land use
density of streets and highway networks
natures of travel patterns
Urban Areas: places within boundaries set by responsible State and local officials having a population above 5,000 people
Urbanized (>=50,000) Small urban (5,000-50,000)
Rural Areas: everything else

21. Rural Functional System
Rural Principal Arterial (Interstate)
Rural Minor Arterial (Intercity, Intertowns)
Rural Collector System (Intracounty)
Major Collectors
Counties and towns not served by higher systems
Minor Collectors
Accumulate traffic from local roads
Rural Local Road System
Access to land adjacent to collectors

22. Rural Highways Systems Percentage Principal arterials 2-4%
Principal + Minor Arterials
7-10%
Collectors
20-25%
Local roads
60-75%

23. Urban Functional System
Urban Principal Arterial
Urban Minor Arterial Street
Urban Collector Streets
Urban Local Road System

24. Urban Highways Systems Percentage Traffic Volume Length
Principal arterials
40-65%
5-10%
Principal + Minor Arterials
65-80%
15-25%
Collectors
Local roads
10-30%
60-80%

25. Wright and Dixon (2004) Figure 1-3

26. Wright and Dixon (2004) Table 1-1

27. Wright and Dixon (2004) Table 1-2

28. Reauthorization of FAST Act
The Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) was enacted August 10, , as Public Law TEA-21 authorizes the Federal surface transportation programs for highways, highway safety, and transit for the 5-year period
The Moving Ahead for Progress in the 21st Century Act or the ‘MAP-21’ was passed by the Senate in March 2012 and the House on June 29th, President signed it on July 6th, Total budget: $105.2 billion (27 months).
H.R. 3763: Surface Transportation Reauthorization and Reform Act of Passed on Dec 2nd, 2015; effective in The $305 billion bill reserves $48 billion exclusively for transit and $205 billion for highways. The bill expires in ( More info: