Review your existing bicycle and pedestrian count program and create an inventory. In addition to transportation staff, reach out to parks departments, business districts and health departments in your area. All are potential data collectors.
As data sources are found, categorize them into permanent count stations and short duration counts:
- Short duration counts can be from one hour to multiple months and can be collected by hand or machine.
- Permanent count stations are automated counters that count continuously 24-hours per day for at least one year at a given location.
Below are the essential questions to ask:
- Where are they counting?
- What are they counting?
- What technology do they use?
- How long have they been counting there?
- When, how often, and for how long do they count?
- Are these intersection counts or counts on a road or path segment?
- Has count accuracy been evaluated?
Once you have inventoried the count data, the next step is to assemble it into one useable format. Multiple regions are working on web-based bicycle and pedestrian clearinghouses which can share and accept data. Examples of these are shown under resources, below.
The Minnesota Department of Transportation published a report in 2013, which describes its inventory of the state’s bicycle and pedestrian count programs and offers recommendations.
The Los Angeles metropolitan area has a bicycle count data clearinghouse which recommends manual count formats, allows partner agencies to upload data and makes the data publicly available.
In the Philadelphia metropolitan area, the Delaware Valley Regional Planning Commission (DVRPC) provides online access to its bicycle and pedestrian counts.
Similarly, Arlington, Virginia offers access to their count data through an online site which allows data to be sorted by weather and time.
Many other jurisdictions are offering their bicycle and pedestrian count data in various formats online. Below is a partial list:
• Boulder, Colorado
• Minneapolis, Minnesota
• New York City, New York
• Portland, Oregon
• Seattle, Washington
Unfortunately, many of the sites above to do not show all of the count data available in a given city or region. For example, the Boulder site only shows short-duration bicycle and pedestrian counts collected as part of the regularly motor vehicle counting program, and does not provide access to data from their many permanent bicycle count stations.
For this reason, more efforts on creating centralized data clearinghouses for bicycle and pedestrian count data are needed. To that end, the National Institute of Transportation and Communities (NITC) has assembled a pooled-fund of local, regional, state and federal agencies, which will create an online national data archive for non-motorized traffic count data. Work on the archive is scheduled to start in March 2014. For more information, contact Hau Hagedorn.
The review of existing continuous counts should review and assess the following:
Overall Program Design
If existing continuous count data is available, it should be analyzed to determine typical traffic patterns and profiles:
Note that the count magnitude may not be similar, but the time-of-day, DOW, or month-of-year patterns may be similar in shape or overall profile. These patterns of variation will ultimately be used to create groups of similar locations (called factor groups) that can be used to factor (i.e., annualize) short-duration counts to an annual volume estimate. If continuous non-motorized count data is not available, short-duration counts can be used to estimate the traffic patterns that may be typical. However, because of the higher variability of pedestrian and bicyclist count data, short-duration counts should be used with great caution. Short-duration counts cannot be used to determine monthly variability and, depending on the duration of the counts, may not be indicative of typical DOW variability. In addition, inclement weather or other special events may skew the time-of-day patterns in short-duration counts. In most cases, some data is better than no data in establishing typical traffic patterns.
In reviewing the current program and existing non-motorized data, one should also understand the basics of how data is processed by the field equipment and loaded into its final repository, whether that be a stand-alone spreadsheet, a mode-specific database, or a traffic monitoring data warehouse. The following elements should be considered:
Subjective data manipulation or editing should be avoided. Instead, appropriate business rules and objective procedures can be used in combination with supporting metadata to address missing or invalid data.
The final step in reviewing the existing program is to consider summary statistics, both those that are currently computed as well as those that may be needed. Permanent count locations should be providing count data 24 hours per day, 365 days per year; however, this continuous data stream is often summarized into a few basic summary statistics, like annual average daily traffic. Because of the greater monthly variability of non-motorized traffic, other summary statistics may be more relevant:
The review of existing and needed summary statistics should be based on those users and uses that have been identified earlier in the process. In this way, one can ensure that that variety of users has the required information to make decisions.