What is a transit bulb?
A transit bulb, also known as a curb extension or bulb-out, is a traffic calming measure used to improve pedestrian safety and accessibility at intersections or mid-block crossings. It is a section of the sidewalk or curb that extends into the roadway, effectively narrowing the street and reducing the crossing distance for pedestrians.
How Transit Bulbs Work
Transit bulbs work by extending the sidewalk or curb into the street, typically at intersections or mid-block crossings. This serves several purposes:
- Reduced Crossing Distance: By narrowing the roadway, transit bulbs shorten the distance pedestrians must cross, making it safer and more convenient for them to traverse the street.
- Increased Visibility: The extended curb makes pedestrians more visible to approaching drivers, improving safety at crossings.
- Traffic Calming: The narrowed roadway caused by the transit bulb encourages drivers to slow down, further enhancing pedestrian safety.
- Improved ADA Accessibility: Transit bulbs provide a more level surface for wheelchair users and others with mobility challenges, making it easier for them to cross the street.
Transit bulbs are often used in urban areas with high pedestrian traffic, such as near schools, transit stops, or commercial districts, to create a safer and more accessible environment for people on foot.
Design Considerations for Transit Bulbs
When designing and implementing transit bulbs, there are several key factors to consider:
- Curb Radius: The curvature of the extended curb should be carefully designed to accommodate the turning radius of larger vehicles, such as buses or emergency vehicles, while still effectively narrowing the roadway.
- Drainage: Transit bulbs must be designed to ensure proper drainage, preventing the accumulation of water or debris that could create hazards for pedestrians.
- Accessibility: The transit bulb design should include features like curb ramps, detectable warning surfaces, and level surfaces to ensure accessibility for all users, including those with disabilities.
- Visibility: Proper lighting, signage, and markings should be used to ensure that the transit bulb is clearly visible to both pedestrians and drivers, especially at night or in low-visibility conditions.
By carefully considering these design elements, transit bulbs can be effectively implemented to enhance pedestrian safety and accessibility in urban environments.
