sitemap Principles of Universal Access

Principles of Universal Access

1.  Universal Access to Destinations
All destinations served by the public road system shall be accessible by pedestrians and by drivers of all vehicles (including bicycles), except that vehicle operation may be restricted for reasons of excessive weight, noise or size, or extraordinary potential for damage to the property or person of others.

2.  Equal Rights of Use
People's right to use that portion of a street designed for travel is not diminished by less weight, less size, or less average speed associated with their travel mode. The adequate accommodation of heavier, larger, faster travel modes by a road's design must not imply its inadequacy for or unintended use by smaller, lighter, or slower modes. Demand-actuated traffic signals must detect and serve a diversity of users including bicycle operators in the roadway and pedestrians using crosswalks.

3.  Integration of Modes
Travel by different modes shall not be segregated by law or facility design without compelling, objective, scientifically valid evidence of operational advantages of segregation that outweigh the disadvantages. Segregation of pedestrian from vehicle traffic may be warranted on busy roads due to the different maneuverability and nighttime visibility characteristics of pedestrians and vehicles. Segregation of different vehicle types is undesirable, as this segregation almost always creates increased conflicts at junctions, forces users of some vehicle types to use inferior facilities, or stigmatizes users who violate the segregation policy for safety reasons.

4.  Uniformity and Simplicity
Transportation systems should be simple and intuitive. Designs and regulations should be uniform across facilities. Similar traffic situations should be treated in a similar manner, enabling more rapid and reliable user behavior. Vehicle-type-specific exceptions to the Rules of the Road are undesirable because such exceptions make traffic movements less predictable and traffic negotiation less reliable.

5.  Accessible Surfaces
To the extent practicable, travel surfaces should accommodate travel on foot with minimal trip hazards and via common assistive devices such as wheelchairs. Roadway surfaces should be as clear as possible of hazards for narrow tires such as bicycle wheels.

6. Crossable Roadways
Crossing distances at non-signalized access locations must not exceed the distance that can be covered at walking speed before traffic may arrive from beyond sight distance, or during reasonable gaps in roadway traffic. Refuges provided to reduce crossing distances should be large enough to store assistive devices such as wheelchairs and strollers. Traffic signal timing should provide adequate clearance intervals for safe crossing by pedestrians and slow vehicles.

7.  Appropriate Space for Use
Adequate space for maneuvering and recovery should be incorporated for all vehicle operators and for pedestrians including wheelchair users. If it is desirable to accommodate faster speeds for some modes while slower modes are present on the same road, the road may be designed to facilitate easier overtaking between modes. Overtaking activities should take place at distances appropriate for the difference in speed, maneuverability of modes, and vulnerability of users.

"Freedom of movement is the very essence of our free society ... once the right to travel is curtailed, all other rights suffer." 
--Justice William Douglas, U.S. Supreme Court


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