Perils for Pedestrians

TV talk about people who walk

Sidewalk Placement

What are the advantages of setting back the sidewalk with a planting strip?

Sidewalks can be built right at the edge of the street ..... or sidewalks can be separated from the curb by a planting strip, that is just several feet of grass between the sidewalk and the street. What a difference this green space can make!

We can think of more than a dozen benefits from planting strips. Click on any photo for a larger view.

Increased pedestrian safety. Every now and then, a reckless driver will run up on the sidewalk. The extra separation makes that less likely.
Increased pedestrian comfort. It is very uncomfortable for pedestrians to walk close to traffic. A green buffer makes a world of difference.
Provide clearance from side mirrors. Side mirrors and overhanging cargo on large vehicles can stick over the curb. A setback keeps pedestrians beyond their reach.
A place to plant trees. In the summer, pedestrians welcome the shade provided by a row of street trees. Trees also provide substantial environmental benefits.
To provide a place to absorb runoff when it rains. The environmental impact of sidewalks is minimized when a wide grassy area separates sidewalks from the gutters and storm drains.
To keep the apparent street width narrow. Sidewalks at the curb will make a street appear wider, encouraging drivers to go fast. Sidewalks set back behind a planting strip will not contribute to a wider appearance, particularly where trees are planted in the space.
A place to put fire plugs, utility poles, and road signs. Without a planting strip, they can form permanent obstructions in the middle of the sidewalk.
A place to dump snow. Plows pile snow high along the curb. If the sidewalk is built at the curb, it will be buried under the deepest part of the mound.
A place to pile leaves for recycling. Without a planting strip, the only alternatives are to either block the sidewalk or clog the gutter and storm drains.
A place to put trash cans and recycling bins. Every week, once or twice a week, trash cans will block the sidewalk if there is no planting strip.
To discourage parking on the sidewalk. Physical separation from the street can do more to discourage this obnoxious practice than typically lax law enforcement.
To provide space for groups of pedestrians. When children (or older pedestrians) travel in a group, they will not fit on a narrow 4 or 5 foot sidewalk. If the sidewalk is set back behind a grassy strip, they will spill over onto the grass rather than into the street.
To direct pedestrians to desired crossing locations. Pedestrians are less likely to cross the street where they have to cross grass to get to the street. A grass strip will gently encourage pedestrians to use crossings with paved access points.
To help drivers identify pedestrians about to cross. When the sidewalk is at the curb, all pedestrians are just a step away from crossing the street. When the sidewalk is set back, pedestrians planning to cross the street will have moved away from pedestrians just walking along the sidewalk.
To reduce problems with dips and cross slopes at driveway aprons. This is particularly important for pedestrians using wheelchairs.
To help drivers spot driveways. When the sidewalk is at the curb, the entire length of the curb is paved. A grass strip at the curb will make driveways stand out.
To facilitate curb cuts at corners, especially when combined with a tight corner radius. If the setback of the sidewalk is greater than the corner radius, curb cuts in line with the sidewalk will be on the straight portion of the curb and will face the crosswalk.
A place to put street furniture. In business districts, the grass is replaced by pavement to create a "furniture zone". Benches, bike racks, newspaper boxes, and other street furniture occupy the area between the curb and the "travel zone" of the sidewalk.
A place to put storm drains out of the street. Storm drains can be recessed into the green space, keeping steep inlets and metal grates out of the curb lane. A typical in-street storm drain can be a hazard to bicyclists, particularly with an outdated "bike-trap" design. It is a maintenance headache to keep from getting clogged. And pavement is subject to premature failure around the drain.
To reduce the amount of road spray striking pedestrians in wet weather. In addition to the dramatic major splash from a puddle, cars generate a tremendous amount of fine spray close to the roadway.
To improve air quality above the sidewalk. Exhaust fumes are most concentrated closest to the center of the traffic stream. Moving the sidewalk away from traffic will keep pedestrians out of the highest levels of pollution.
To provide a wheelchair recovery zone. If a wheel goes off the edge of a curb, a wheelchair user will fall into the street. If there is a grassy space between the sidewalk and the curb, the wheelchair will remain upright and the wheelchair user can roll back onto the sidewalk.
To provide a "toddler recovery zone". If a small child slips away from a parent, there will be a few moments to catch them before they enter the street.
To protect a falling pedestrian. If a pedestrian loses their balance or trips and falls, they might land in the street if the sidewalk is adjacent to the curb. A grassy space next to the sidewalk will keep a falling pedestrian out of the street.

How wide should the planting strip be? A planting strip of six to ten feet (two to three meters) will provide all of the above benefits. Much wider and it would start to disconnect the sidewalk from the road, which can be a problem if it puts pedestrians out of the line of sight of drivers about to turn a corner. A narrow planting strip of just three feet (one meter) is far better than nothing, but will not be able to provide all the benefits of a wider strip.

John Z Wetmore
john@pedestrians.org
Producer of "Perils For Pedestrians",
The monthly cable television series.
http://www.pedestrians.org