Pedestrian Safety Guide and Countermeasure Selection System
Back-in diagonal on-street parking. Source: pedbikeimages.org - Carl Sundstrom (2008)
On-street parking can be both a benefit and a detriment to pedestrians. On-street parking increases positive “friction” along a street and can narrow the effective crossing width, both of which encourage slower speeds. Parking can also provide a buffer between moving motor vehicle traffic and pedestrians along a sidewalk. In addition, businesses that rely on on-street parking as opposed to parking lots are more geared toward pedestrian access; they are more likely to orient their building to the sidewalk. This attention can foster a more vibrant pedestrian commercial environment.
On the other hand, parking creates a visual barrier between motor vehicle traffic and crossing pedestrians, especially children and people using wheelchairs. Therefore, where there is parking, curb extensions (also called bulb-outs) should be built where pedestrians are expected to cross the road. Also, parking should be restricted at least 20 feet on both approaches to a marked or unmarked crosswalk.
Diagonal on-street parking has been provided on some downtown streets to provide additional parking and create "friction" for drivers (leading them to drive more slowly) that improves the pedestrian environment. Diagonal parking may require more attention to improve visibility at crossings and intersections, and it should not be used on high speed or busy streets. Back-in diagonal parking is preferred and has a number of advantages over pull-in parking, including: giving drivers access to their trunk from the curb rather than the street, protection of children as an open door directs them to the sidewalk, and giving the driver clear sight lines when pulling out of the parking space.
It is also important to consider the pricing of on-street parking. By charging the market-rate price for parking and ensuring that parking is not undervalued, people will be more likely to use alternate modes of transportation to reach their destinations. Free or undervalued parking creates an incentive to drive and encourages people to leave their cars for long periods of time. Donald Shoup, a parking expert and planning theorist, suggests setting parking prices to achieve a 12.5 percent vacancy, which effectively curtails driving, but also ensures that convenient parking is available for short shopping trips.6
Additional information on a variety of parking enhancements can be found at “Model Design Manual for Living Streets.”7 For a comprehensive look at back-in/head-out angle parking, see the 2005 report by NelsonNygaard Consulting Associates.8