How does the edge height of curb ramps obstruct bicycles?

Area of Science:

• Civil Engineering
• Human Factors Engineering
• Materials Science

Background:

• Current curb ramp standards may not adequately address the safety and accessibility needs of cyclists.
• Bicycle safety is a growing concern in urban infrastructure design.

Purpose of the Study:

• To empirically evaluate the performance of different curb ramp designs for bicyclists.
• To recommend revisions to existing curb ramp standards based on experimental data.

Main Methods:

• Four types of curb ramps were tested: concrete (50 mm edge), reinforced concrete (50 mm edge), plastic (20 mm edge), and recycled rubber (10 mm edge).
• Twenty subjects ascended ramps on bicycles at approach angles from 15 to 90 degrees under wet and dry conditions.

Main Results:

• All subjects successfully ascended all ramps at approach angles of 45 degrees or greater, regardless of conditions.
• Ascent was impossible on concrete ramps at a 15-degree approach in wet conditions and difficult in dry conditions.
• Ascent was challenging on reinforced concrete ramps at a 30-degree approach in wet conditions.

Conclusions:

• Curb ramps with 50 mm edge heights present significant challenges for bicyclists, even in dry conditions.
• It is recommended that curb ramp edge heights be reduced to below 50 mm to enhance cyclist safety.
• Approach angle and surface conditions (wet/dry) critically impact curb ramp usability for cyclists.