Dr. Smith is a principal of a school and is very interested in working with his regional Metropolitan Planning Organization (MPO) to improve the safety of the transportation
infrastructure around his school, in hopes that it enables more students to walk or bike to school.
Improving the minutes of physical activity students receive daily is of major importance to the school, as new evidence suggests a relationship between school performance and physical activity. However, Dr. Smith is also aware that safety is important, so she wants to better understand the best options. The tools developed through this project can help Dr. Smith work with her regional MPO to identify the preferred infrastructure investments that would achieve multiple public health objectives.
The first step is for Dr. Smith to identify and recruit data collectors. Field data is necessary to calculate the safety indices, the Pedestrian Safety Assessment Index (PSAI) and the Bicyclist Safety Assessment Index (BSAI), and the physical activity indices, the Walkability Assessment Index (WAI) and the Bikeability Assessment Index (BAI). If Dr. Smith has a partnership with a university or a high school or other nonprofit organization, she is encouraged to draw upon volunteers or students to conduct the inventory and collect the data necessary to perform the analysis. If she does not have such a partnership, she could work with the teachers and parents in the school to collect the necessary data. Involvement of others in the process of evaluation and inventory is valuable as it can raise broader community awareness of the relationship between transportation and public health.
Next, a training session needs to be designed to prepare the data collectors to inventory the transportation infrastructure around the school. The data collection teams enter the field to collect data after completing the training. After all the necessary data is collected, it must be entered into the appropriate Excel spreadsheets for analysis (in the appendix of this chapter and available on the website of the Transportation Research Center for Livable Communities). The Excel spreadsheets include the appropriate weights for each transportation element and
elemental option so an overall index number can be calculated. Entering the data into the Excel spreadsheet produces scores that can be plotted in the Performance Measures Plots, to
determine how the existing transportation facility affects public health objectives. Each step in the process is elaborated below.
Step 1. After the data collection team has been recruited, the team would attend a 60-minute training session to prepare them for data collection in the field. Training manuals are provided in the appendix of this chapter for the training session (Appendix 7A-PA Inventory Manual and Appendix 7B-Safety Inventory Manual). Two manuals are prepared to educate data collection volunteers on the different elements of the infrastructure for the assessment of safety, air quality and physical activity. The first manual covers physical activity and the second manual covers safety. The manuals are divided into subsections: Intersection and Segment for Pedestrians and Bicyclists. Survey forms are prepared for each of these modules and sections. Students (or community volunteers) can use these inventory forms for collecting data on transportation infrastructure elements data in the field or virtually (online using google earth). Each manual discusses the different types of infrastructure elements and definitions that the data collectors need to know before collecting data related to the selected public health objectives. Visual aids are also included to illustrate possible infrastructure elements and options. The visual aids will help data collectors identify the elements of the transportation infrastructure in their area of study. At the end of the training, the data collection team should be required to evaluate one
road segment and one intersection using each inventory to make sure all data collectors are using the materials correctly.
Step 2. After successfully completing training, two-person teams should be assigned to collect data on the road segments and intersections surrounding the location, in this case the school.
Each road segment and intersection should be assigned a segment or intersection number for data entry purposes. Assigning duplicate teams to the same segment or intersection can enhance the reliability of the data collection as it allows one to check for inter-rater reliability. Division of labor can be based upon the number of volunteers. The forms that match the data collection responsibilities of the two-person teams are listed in Table 7.2.
Table 7.2 Team Data Collection Responsibilities and Required Forms Team Number Infrastructure Public Health
Objective
Mode Type
Form
1 Segment Safety Bicyclist Bike Safety Segment
1 Intersection Safety Bicyclist Bike Safety
Intersection
2 Segment Safety Pedestrian Ped Safety Segment
2 Intersection Safety Pedestrian Ped Safety
Intersection 3 Segment Physical Activity Bicyclist PA Bike Segment 3 Intersection Physical Activity Bicyclist PA Intersection 4 Segment Physical Activity Pedestrian PA Walk Segment 4 Intersection Physical Activity Pedestrian PA Intersection Step 3. The teams are sent into the field to inventory the infrastructure. The inventory is a survey that contains a checklist of questions with close-ended options. It is relatively simple to complete while in the field.
Step 4. After collecting the data, the teams should submit the data collection to one team or assigned individual, which would be responsible for entering the data entry into the respective Microsoft Excel sheet for the necessary analysis. After the data is entered into a database, responses are converted into binary responses and then index values are calculated (Excel formulas are pre-programmed into the workbook). An example is provided in the first column of each Excel spreadsheet. Table 7.3 presents a list of the Excel sheets and numbers that correspond to the different field inventories.
Table 7.3 Crosswalk Between Excel Spreadsheets and Field Inventories Team Number Inventory Form Excel Spreadsheet
1 Bike Safety Segment 5. Bike Seg Safety 1 Bike Safety Intersection 3. Bike Int Safety 2 Ped Safety Segment 4. Ped Seg Safety 2 Ped Safety Intersection 2. Ped Int Safety
3 PA Bike Segment 6. PA Seg Bike
3 PA Intersection 1. PA Int Walk/Bike
4 PA Walk Segment 7. PA Seg Walk
4 PA Intersection 1. PA Int Walk/Bike
Step 5. The Excel spreadsheet is formatted to calculate a value for each segment and intersection in each direction (East Bound/North Bound or West Bound/South Bound). The overall score will be calculated and appear at the end of each column. This score can then be located in the appropriate Performance Measures Plot to determine its overall impact on public health.
For example, consider the segment scores provide in the Excel spreadsheets for the hypothetical segment, Segment 101. If Dr. Smith is interested in knowing how Segment 101 influences the public health dimensions of physical activity and safety, she looks up the scores calculated in Spreadsheet #7, PA Segment Walk, and Spreadsheet #4, Ped Seg Safety. Spreadsheet #7 provides two scores, .36 (EB/NB) and .34 (WB/SB), one for each direction. Spreadsheet #4 also provides two scores for each direction, .43 and .42. These values can then be plotted in the Safety and Walkability Segment Plot, Figure 7.1 above. The plot location suggests this is a segment that is relatively safe and walkable as all scores fall into the green areas. Dr. Smith could also use the spreadsheets to determine how the safety or walkability of this segment could change if certain elements are added or different options are considered. Table 7.4 presents the crosswalk between the Excel Spreadsheets and the Performance Measures Plots.
Table 7.4 Crosswalk between Excel Spreadsheets and Performance Measures Plot Public Health
Objective
Scores to Consider Excel Spreadsheet Performance Measures Plot Safety Bicyclists-Segment 5. Bike Seg Safety Safety and Bikeability
Segment Plot
Bicyclists-Intersection
3. Bike Int Safety Safety and Bikeability Intersection Plot Pedestrian-Segment 4. Ped Seg Safety Safety and Walkability
Segment Plot
Pedestrian-Segment 2. Ped Int Safety Safety and Walkability Intersection Plot Physical
Activity
Bikeability-Segment 6. PA Seg Bike Safety and Bikeability Segment Plot
Walkability and Bikeability-Intersection
1. PA Int Walk/Bike Safety and Bikeability Intersection Plot and Safety and Walkability Intersection Plot Walkability-Segment 7. PA Seg Walk Safety and Walkability
Segment Plot
As mentioned previously, the index scores and plots presented here do not account for traffic or other social or behavioral characteristics of the population that may influence public health outcomes. Therefore, Dr. Smith is advised to use these tools as a way to quantify the performance of the transportation infrastructure; however, final decisions must also take into consideration other features that are unique to the particular context.