Create a Fact-Base: Document Locations of Existing Facilities and Their Use
A plan is built on a fact-base. Communities can have many public or quasi-public facilities that provide various services to pedestrians and bicyclists. Documenting the presence and status of these facilities allows agencies to identify and prioritize locations where improvements are needed. Knowing where current or potential pedestrian and bicycle use is high also enables agencies to focus planning efforts on areas where the benefits would be maximized.
Existing infrastructure
Traditional infrastructure elements include: sidewalks and bicycle/pedestrian paths. However, including other community elements—essential to understanding where pedestrians can and cannot go and the quality of the pedestrian infrastructure—is imperative. Following is a list of information that could be collected:
- Street light inventories—single versus double sided lighting, spacing of lights, and the size of lights (level of illumination)
- Crosswalk inventories—location and type of crosswalk markings (especially helpful for maintenance activities)
- Inventories of bus stops, school locations, crosswalk locations, and school-related signs
- Inventories of road facilities (local streets, collectors, arterials, thoroughfares, highways) and any pedestrian-related infrastructure they may have
- Inventories of pedestrian warning signs, crosswalk location signs, and school-related signs and the last dates when the signs were replaced (to ensure reflective signs are in place)
These data are regularly available in a local planning department, or for metropolitan areas, in a metropolitan planning organization (MPO). Geographic information systems (GIS) can also be used to display the location of these facilities.
In addition to knowing the location of the facilities, knowing about their current characteristics is important. Is the infrastructure well-maintained? Is it connected to other parts of the network? This information is rarely available, but can be collected using community audits or facility inventories. A useful report is the FHWA Pedestrian and Bicycle Date Collection in United States Communities: Quantifying Use, Surveying Users, and Documenting Facility Extent. The report documents existing data collection efforts from 29 different communities, summarizes results, and discusses lessons learned.
Current use
Knowing current and potential pedestrian and bicycle demand is useful for prioritizing investments. For current users, questions include:
- Where are pedestrian and bicycle activities taking place?
- What are the demographic characteristics of non-motorized transportation users?
- What are barriers that impede additional walking or bicycling?
Actual users can be identified through surveys or site counts. Surveys are commonly implemented at the trail, corridor, or community-level. They can be conducted over the phone, in person, or via the internet; each method has different cost and response implications. The length of the survey matters, with short surveys providing limited information but yielding higher rates of response than longer surveys.
The geographic scope for the survey will depend on the specific purpose of the data collection effort. For examples of recent surveys, see pages 92 to 120 of the report, FHWA Pedestrian and Bicycle Date Collection in United States Communities: Quantifying Use, Surveying Users, and Documenting Facility Extent.
Counts most often occur at specific points (e.g., intersections or midblock), although recent research has tested ways of collecting pedestrian activity data by repeatedly traversing streets while simultaneously recording counts. Technologies for counts include:
- Manual
- Infra-red laser and passive sensors
- In-pavement loop detectors
- Piezo-films
- Pneumatic tubes
- Video
For examples of how these technologies have been used in US communities, see pages 21 to 91 of the report, FHWA Pedestrian and Bicycle Date Collection in United States Communities: Quantifying Use, Surveying Users, and Documenting Facility Extent.
Data collection is expensive, but many agencies have developed innovative approaches to reduce the cost of collecting such data, including using shared technologies, volunteer labor, and piggy-backing pedestrian and bicycle data into current motorized vehicle data collection programs.
Potential use—predicting pedestrian and bicycle use
As cities and towns begin the work of redeveloping their transportation systems to support bicycling and walking, the list of needed improvements far outstrips available dollars. Often improvements will serve areas where there is no current pedestrian or bicycle travel, perhaps because conditions on the ground engineer out any possibility of traveling via non-motorized modes. In such cases, planners will need to identify areas where the latent or repressed demand for travel by walking or bicycles is high.
The question that planners have begun to ask is this: if we build this sidewalk (or path, etc.), how many people can we expect to use it?
Finding the answer is the fundamental aspect of predicting demand. Transportation planners have been asking (and answering) this question for motor vehicular travel since the late 1960s, when the first travel demand models were developed. By contrast, researchers are only just beginning to scratch the surface of these topics for pedestrians and bicyclists.
For pedestrians and bicyclists to have a seat around the transportation table, it is important to acknowledge that some level of analysis must also be done for these modes. Transportation planners have a responsibility to ensure that public funds are being spent wisely—in locations where a larger number of people will benefit from new facilities. Finally, there is a growing trend to quantify the air quality benefits (and congestion relief) that can be expected as a result of CMAQ (Congestion Mitigation and Air Quality) projects. For pedestrian and bicycle facilities, this means coming up with some way to determine how many auto trips will be diverted.
While the science of predicting bicycle and pedestrian travel demand has not yet developed to the same level as motor vehicle planning, there are a number of methods that planners have developed over the years to help quantify which locations have higher levels of demand. When planning bicycle and/or pedestrian facilities, it is important to remember that current volumes usually do not reflect demand for two reasons:
- Existing conditions and gaps in the network result in fewer users—potential users are deterred by dangerous or inconvenient conditions.
- Dispersed land uses create trip distances that are perceived as being too far to make on foot or by bicycle.
Intuitive/Sketch Plan Approach
There are two methods of determining demand for pedestrian facilities: the intuitive approach versus the use of forecasting models. The intuitive approach is less time consuming; however, it does not yield precise results. This type of planning analysis is also called a "sketch plan." A sketch plan typically focuses on proximity between origins and destinations, since distance is a primary factor in the initial decision to take a walking or bicycling trip. According to the Nationwide Personal Transportation Survey (NPTS), the majority of pedestrian trips are 0.4 km (0.25 mi) or less, with 1.6 km (1 mi) generally being the limit that most people are willing to travel on foot. In other words, most people are willing to take a five to ten minute walk at a comfortable pace to reach a destination.
NPTS data also shows that land use patterns and population density have a big impact on trip distance. Higher density communities with mixed land use patterns will have higher levels of walking because destinations are more likely to be located within walking distance of homes and businesses.
For an intuitive (i.e., sketch plan) approach, destinations throughout the study area that would attract pedestrians are shown on a base map. Routes are selected that serve higher concentrations of destination points, or that serve destinations that typically yield high numbers of pedestrians, such as universities, downtown areas, shopping centers, major employment centers (hospitals, business parks, major industries and corporations, etc.), schools, and parks. Route selection and prioritization can be done via graphical representation; the intent is to identify locations that serve multiple destinations and higher population densities (population densities can be obtained from census data). This methodology can be accomplished using a GIS system or it can be done by hand.
Public involvement is important to the success of the intuitive (sketch plan) method. It is particularly important to gain input from a wide variety of local citizens (representing different geographic areas) who represent all ages and abilities.
Forecasting/Modeling Approach
The other method of estimating latent bicycle and pedestrian travel demand is to adjust conventional motor vehicle travel demand theory so that it applies to bicycle and pedestrian travel. By using a gravity model to measure latent bicycle and pedestrian travel demand, the planner can achieve results that are more precise than the intuitive approach. The other advantage to this approach is that it complements the type of analysis that is typically done for motor vehicle and transit travel simulation. This can be particularly important in cases where pedestrian improvements are competing for similar funding mechanisms as other modes, since most transportation improvement programs make funding decisions based upon quantifiable results.
Pedestrian travel demand modeling can be done on a system-wide basis, or at the corridor level. Further information on more precise bicycle and pedestrian travel demand methods are provided in the 1999 FHWA Publication, Guidebook on Methods to Estimate Non-Motorized Travel.