By Jeffrey Siewert, PE
City sidewalks, busy sidewalks, dressed in holiday style …
’Tis the season when safe sidewalks are especially appreciated. Shoppers, carolers, mail carriers, and perhaps even Santa’s elves are busy going to and fro from streets to doorways. Well-designed sidewalks help keep all that foot traffic moving.
Why build sidewalks? Here are a few reasons:
- Sidewalks help keep pedestrians and motorists separated and safe. The Federal Highway Administration (FHWA) notes that 4,500 pedestrians are killed each year in traffic crashes with motor vehicles; almost 8% of those deaths involve pedestrians who were walking along the roadway.
- Sidewalks enhance mobility for everyone – people using wheelchairs, parents with kids in strollers, people who need access to public transportation – everyone needs a safe way to get from Point A to Point B.
- Sidewalks promote wellness and social activity by providing a safe place to walk and making sure that space is wide enough for people to walk side by side.
- Sidewalks provide connectivity in a community, creating safe walkways from residential to commercial and public areas.
Not all sidewalks are created equal, however. We all have had the unpleasant experience of tripping over a cracked sidewalk or feeling less than safe because the sidewalk is too close to the roadway. Following are six basic elements for a safe, useful sidewalk.
1. Separation from traffic
The FHWA says that the wider the separation between the pedestrian and the road, the more comfortable the sidewalk is for the pedestrian. That buffer space also provides room for underground utilities, room for snow storage in northern climes, and room for aesthetic features, such as decorative lighting, planters, and other landscaping.
2. Safe and sturdy materials
A sidewalk should be constructed of a level (2% maximum cross slope – an Americans with Disabilities Act [ADA] requirement), hard, slip-resistant material – that’s generally concrete. Other less expensive materials can be used, such as asphalt or crushed stone, if they are properly maintained. Concrete is more expensive than asphalt, but it lasts longer and is easier to maintain. Pavers are nice due to their aesthetic value and ability to develop geometric graphics – even snowflakes! However, they must be strategically placed on a well-prepared base to avoid settling.
3. Effective drainage
Kids like to splash in puddles, but most adults like to keep their feet dry. If a sidewalk is waterlogged, pedestrians are more likely to walk in the street, which defeats the purpose of keeping pedestrians out of the roadway. Sidewalks should be well-drained. The ADA requirements for cross slope are more than adequate for drainage. But the runoff needs a place to go. If trapped by adjacent soils, sod, landscape, mulch, tree roots, or reindeer tracks, it will be unsafe and unpleasant to use. Designers need to ensure that runoff flows off!
4. Accessibility/universal design
The ADA mandates that a sidewalk needs a minimum clear width of 36 inches. While that’s the minimum to allow a wheelchair user to pass along a sidewalk, the preferred width of an urban sidewalk is 5 to 6 feet. That’s enough to allow two people to walk side by side – maybe not you and Santa Claus, but two average people. The ADA also provides guidelines on safe curb ramps and warning strips needed at the bottom of the curb ramps that can be detected by foot or by cane.
5. Proper maintenance
A smooth sidewalk is safer for everyone. Sidewalks can be damaged by tree roots, heat buckling, and ground swelling. Adjacent landscaping also needs to be maintained so trees and bushes don’t block the sidewalk or obstruct visibility. Let your public works department know if a sidewalk has been damaged. And if you own a home adjacent to a sidewalk, keep an eye on your landscaping to make sure pedestrians can easily use the sidewalk. You don’t want to delay your packages being delivered.
6. Aesthetic elements
A tree-lined sidewalk provides shade as well as aesthetic appeal. Street furniture such as benches and kiosks invite people to stop and enjoy the neighborhood. Street lighting improves visibility and security. All these elements turn a basic sidewalk into a destination.
Sidewalks are part of Complete Streets design, which considers the needs of pedestrians, bicyclists, and motorists when developing new or improved roadways. They make our world a little safer for everyone – and that’s about the best gift anyone can get.
Jeffrey Siewert is a registered professional engineer based in our Tampa-Hidden River Parkway office. He has designed many projects that promote pedestrian-focused transportation and meet community multimodal needs. (However, most of his projects don’t need to provide room for snow storage.)