This four-leg intersection is analyzed assuming 1 lane on the major street approach (Shafor Boulevard) and 1 through lane on the minor street approach (Telford Avenue), resulting in the following:
Warrant #1. No hours of the TMC period exceeded the warrant #1 thresholds shown in OMUTCD Table 4C-1 for condition A, B, and combo warrant (evaluated at 80%). Warrant #1 is NOT satisfied.
Warrant #2. The minimum threshold for vehicles per hour on the higher volume, minor side street approach is 60 vehicles when evaluating warrant #2 at 70% criteria. The highest observed minor side street volume is 34 vehicles. Warrant #2 is NOT satisfied.
Warrant #3. The minimum threshold for vehicles per hour on the higher volume, minor side street approach is 349 vehicles when evaluating warrant #3 at 70% criteria. The highest observed minor side street volume is 18 vehicles. Warrant #3 is NOT satisfied.
Warrants #4 and #5. A total of 618 pedestrians were observed crossing Shafor Boulevard at Telford during the 8-hour data collection periods. Due to the intersection being located on the property corner of Edwin D Smith Elementary School, a gap analysis was performed at the intersection to understand the impact of pedestrian crossings without the existing signal.
Gap analysis was performed using a Poisson Distribution methodology to determine if an acceptable number of gaps are available to cross Shafor Boulevard at the AM, midday, and PM peak hours. Acceptable numbers of gaps to accommodate pedestrians are assumed to be one per minute (60 gaps per hour). The available number of gaps is dependent on total bidirectional volume on Shafor Boulevard, crossing distance from curb ramp to curb ramp (measured at 60 ft), and walking speed (3.5 ft/s was assumed). The available gaps during peak hours were calculated using the following equation:
- λ = Total bidirectional volume at Shafor Blvd @ Telford Ave
- t = Crossing Time = 60 ft3.5 fts = 17.1 seconds
The resulting number of gaps for each peak hour volume are shown in Figure 19A.
The gap analysis shows the calculated number of gaps to cross Shafor Boulevard is over 75 at this intersection during peak hours. The acceptable number of gaps is 60 per hour (i.e., one opportunity to cross every minute). With acceptable headway available to cross the major street at this location, warrants #4 and #5 are NOT satisfied based on gap analysis.
