Agenda - 12-19-1995 - X-A - Laserfiche WebLink

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10 B. Data Collection-Bicycle routes studied were segmented into homogenous units for data collection. Speed limit, traffic volumes, and lane width determined segment length. Data was collected through research of NCDOT files and field measurement. Research of NCDOT documentation included cataloging lane widths, speed limits, and average daily traffic. Field data collection was used to verify the NCDOT data and to collect additional data for the Town of Hillsborough maintained streets. C. Bicycle Stress Level Concept-The methodology for determining the compatibility of roads for cycling is based on the level of stress caused by different road conditions. Bicyclists "seek to avoid conflict with motor vehicles, harassment from heavy traffic, and the strain of having to concentrate for long periods on riding along narrow, high-speed, high-volume roads. In other words, they want to minimize not only physical effort but mental stress as well." (Sorton 1994) Determination of stress level requires evaluation of the stress level caused by each of three variables of a road segment that have the greatest influence on bicycle/traffic interaction: traffic volume, curb (outside)lane width, and traffic speed. Each of these variables is evaluated for a particular segment. Outside lane traffic volume is the peak hour volume (vph), or average daily traffic on a given street in a 24-hour period multiplied by a constant representing the percentage of daily traffic occurring during the peak period. A value of 10%was used for this analysis and is the accepted estimate of the proportion of daily traffic occurring during the peak period. This value is then divided by two to determine the peak period traffic in one lane. Dividing by two assumes a 50/50 split in traffic between the lanes of a road with one lane of travel in each direction. Outside lane width is measured from the edge of the pavement to the center line. Eight feet of this width is subtracted when the road segment accommodates on-street(parallel) parking. Speed of motor vehicles applies to the posted speed limit. Table 1 below shows the suggested stress level evaluation for each variable. In using this methodology, we chose to follow the stress level evaluations suggested by Sorton. Table 1: Stress Level Calculation for Each Variable Stress Level Outside Lane Outside Lane Speed of Motor Volume* Width feet Vehicles (mph) 1 <,= 50 >,= 15 <,=25 2 150 14 30 3 250 13 35 4 350 12 40 5 >,=450 <,= 11 >,=45 "vehicles per hour per lane 4.