The Williamson County & Cities Health District (WCCHD), located in central Texas, is the local public health department for almost 300,000 residents who live in the county's 1,124 square miles. While WCCHD provides many traditional public health services to residents, it is also responsible for promoting healthy living and healthy communities.
In 1999 WCCHD participated in the Behavioral Risk Factor Surveillance Survey (BRFSS). Conducted by the Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion at CDC, BRFSS is the largest continuously conducted telephone health survey in the world. It monitors modifiable risk factors for chronic diseases and other leading causes of death.
The results showed that 56 percent of Williamson County residents were sedentary, 34 percent were overweight, and 21 percent were obese. Most alarming was that the rate of sedentary individuals was almost double the rate for Texas and the nation. In addition, vital statistical data showed that the most prevalent cause of death for county residents was cardiovascular disease. For a county with a median age of 32 years, the combination of sedentary lifestyles and cardiovascular disease as the major cause of death raised concerns for the future health of residents.
During this time, WCCHD was granted nine AmeriCorps*VISTA positions for a period of three years (2000-2003) to work on the Healthy People 2010 objectives. [Healthy People 2010 is a comprehensive disease prevention program put forth by the United States Department of Health and Human Services.] These VISTA workers worked on projects that encouraged various segments of the population to participate in physical activities. The bicycle program, one of these projects, has two components: the Williamson County Bicycle Map and trail advocacy.
The Bicycle Suitability Criteria
Project staff began by researching existing methods for measuring roadway safety and suitability for bicycling. They selected the Bicycle Suitability Criteria for State Roadways in Texas as a guide for data collection. This report was authored by Shawn M. Turner, C. Scott Shafer, and William P. Stewart of the Texas Transportation Institute in the Texas A&M University System. Research was performed in cooperation with the Texas Department of Transportation. The report specifically addresses the problem of how to develop criteria for evaluating roads for bicycle suitability. Although the objective was the creation of a bicycle map for cyclists, the criteria can also be used to identify deficiencies in regional or intercity bicycle route networks and plan improvements for roadways; these criteria are generalized enough to be used by any state or local entity. For this project, the following types of roadways were selected to survey: city streets, county roads, farm-to-market roads or ranch roads, and state roads.
Many factors can be used when deciding how to evaluate a road. Shoulder width, traffic volume (i.e., average daily traffic), vehicle speed (or posted speed limit), and shoulder or pavement condition were criteria recommended for this project. This data was obtained from a combination of county, city, and state sources.
While much of this information is available from government agencies, it should be noted that files can contain inaccuracies or be out of date. For example, the traffic count data from the county hadn't been updated since 1997. This was a significant issue because Williamson County was one of the top 10 fastest growing counties during the late 1990s. Older data files did not include new roads that were being built. Field evaluation of roadways, traffic counts, posted speed limits, and shoulder widths as well as visual identification of new roadways helped ameliorate this problem.
Collecting Road Data
After viewing the basemap that was generated using Census 2000 TIGER/Line shapefiles in ArcView, the staff identified which roads should be surveyed and created a spreadsheet for field data collection. Due to limited project resources, no electronic devices were available for fieldwork so data collection was done the old-fashioned waypencil and paper. Field-workers also used either a measuring wheel or measuring tape.
Once out in the field, staff divided roadways by intersections. For example, County Road 181 intersects three other roads: Lakeline Boulevard, Bagdad Road, and County Road 272. County Road 181 was evaluated from Lakeline to Bagdad, and from Bagdad to County Road 272. This method provided some logic once data was entered into the ArcView project. Obviously, a more efficient method would be to enter data directly into the database while in the field using a device such as a handheld computer. Once the fieldwork was complete and scores for various factors assigned, the data was entered in the road attribute table. New fields are added in ArcView to accommodate the new data. Data collection took approximately eight months using one or two staff members.
Creating the Map
For the Williamson County bicycle map, the calculated suitability score was color coded. Unrated roads were gray, roads with a score of -1 or less were red, those scoring 0 to 2 were yellow, and roads scoring 3 or more were green. Additional features were added to the map project. Owing to the need for coordinating with individual local governments, data for the hiking and biking trails was the most difficult to obtain. Not all local government agencies use an in-house system for their park and trail plans. Several hiking and biking trails had to be created from scratch for the project. However, the staff was successful in obtaining most of the existing, planned, and proposed trail data. Other data sources for the map are listed below in Table 1.
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