How can I predict sidewalk use?
While most communities routinely collect motor vehicle traffic counts, very few gather pedestrian counts. This means that the data necessary to reliably predict sidewalk use is rarely available. The leading method for predicting walking trips involves a complex model from university research which examines four factors: density, destinations, distance and route directness. A quicker method involves counting existing pedestrian trips to forecast additional use if a sidewalk is constructed.
Researchers have compiled detailed lists of factors that correlate with increases in walking for transportation or for recreation. A key finding is that land uses are more powerful determinants than are the presence of sidewalks. Increasing the number of residents and the number of frequently-visited destinations within a one-mile diameter area will increase the number of walking trips and the likelihood that any individual will walk. Destinations such as grocery stores are powerful trip generators, as are restaurants, coffee shops, taverns and schools. Most shopping malls score poorly as walking trip generators. Though they score high for destination value, surrounding residential density is usually low and distances to the malls are typically high.
The land use model is not practical for someone interested in understanding the local and specific influence of constructing a particular stretch of sidewalk. For this purpose, a group of detail-minded volunteers or a few city employees can gather specific information to gauge latent demand for a sidewalk, using the process outlined here.
- Find a detailed map and descriptive data for the area in question. Use census information
(http://factfinder.census.gov/home/saff/main.html?_lang=en) to estimate the population living within those census tracts. Highlight on the map the origins and destinations within one half-mile of the proposed sidewalk. Estimate the walking trips of greatest likelihood based upon existing land uses. - Observe and count the existing walking trips that take place in those locations. Unless it is completely impossible to walk on a particular stretch of roadway, some people likely will already be walking on the shoulder or in the street. Note who is walking (people with dogs?) and who is not walking (children? seniors?).
- Survey a sample of people in the neighborhood regarding barriers to walking. Ask them to rank a list of five to ten barriers to walking (including the absence of a sidewalk), and to estimate the number of additional walking trips each week they would take for recreation and transportation if a sidewalk were constructed.
Based on these population statistics, counts and surveys, establish a baseline and anticipated number of walking trips. Note that destinations within the study area such as elementary schools or parks may result in larger gains from adding sidewalks. (Ask local schools whether they presently prohibit children from walking because of perceived traffic safety hazards.)
Resources and more information:
US Department of Transportation Federal Highway Administration. (1999). Guidebook on Methods to Estimate Non-Motorized Travel: Overview of Methods (FHWA-RD-98-165). http://drusilla.hsrc.unc.edu/cms/downloads/Guidebook_EstimateNonMotorTravel_Overview.pdf
Information to address lack of sidewalks/sidewalks in poor repair: http://www.walkinginfo.org/problems/problems-sidewalks.cfm
