By Charles Pekow
So many things to think about when estimating bicycle use when planning. Community size, terrain, existing cycling and other transportation facilities, age and other demographic characteristics of the population, climate and so on. How can you consider all the relevant factors when designing bicycle infrastructure as part of any transportation or community development, be it a local project, overall community or regional plan, or corridor?
The National Cooperative Highway Research Program of the Transportation Research Board thinks it has found the best solution so far. In August, it issued Estimating Bicycling and Walking for Planning and Project Development: A Guidebook, which includes a CD, spreadsheets and related tools for figuring out how many people are likely to bike and ride. The guide offers some new methods and includes some ones the program found to be useful.
Planners have often used Census Bureau data or other travel surveys to determine how many people ride bikes. But the program found a lack of consistent methods to understand bicycling and walking activity, and the relationships to demographic, social and physical factors were not well understood. It adds that tools have not kept pace with demand. Most traffic demand tools metropolitan planning organizations use are incompatible with the scale of non-motorized travel, it says.
The program found a need to distinguish between bicycling and walking rather than lumping the two together. Trips by the former average. 2.3 miles; but .7 miles for the latter. They also vary by purpose of the trip. The people who use foot or pedal also differ by demographics such as age, income and education plus the reasons they are going someplace. Also, people tend to be willing to walk or bike further to their jobs than they are to most other destinations. And people are less likely to choose to walk or bike when making multi-stop trips.
Motorized transit not only gets most of the attention because more people use it but because it is easier to predict. It is less dependent on factors such as weather or amount of daylight hours, as many people don’t want to walk or bicycle when it’s dark, cold or raining.
The guide suggests a variety of tools planners could use instead of prescribing a one-size-fits-all plan. It rates the plusses and minuses of each approach. It bases its suggestions largely on use of several successful methods used in the Seattle area and Arlington, Virginia. Also, new global positioning systems (GPS) methods used to track cyclist use have updated traditional method of asking cyclists about their trips. Methods used by the San Francisco County Travel Authority and Portland State University (PSU) that tracked cyclists provided valuable data on the routes they choose. PSU found that waiting times at crosswalks don’t make much difference to cyclists.
But GPS data tell you what hills cyclists will try to avoid but doesn’t help too much in planning. It also tells you what routes cyclists use and where they’re going but not who rides.
You can view, download or order the guidebook and related materials at http://www.trb.org/PedestriansAndBicyclists/Blurbs/171138.aspx. The material is highly technical.
