Example Organizational Objective #2 – Interpretation of Results

With the findings in hand, how can this information help the Northville TIM partners identify improved roadway clearance strategies for lane-blocking incidents? Examining the frequency and cumulative distributions of RCTs for one-lane incidents, it is clear that the partners are consistently clearing the roadway in under 29 minutes (about 71 percent of incidents), and for all one-lane incidents the roadway was cleared in under 60 minutes. As incidents blocking one lane make up the majority of lane-blocking incidents (58 percent), focusing on strategies for clearing one-lane incidents provides the most “bang for the buck.” However, given the current level of performance in clearing one-lane incidents, efforts might be better spent focusing on incidents blocking two or more lanes.

From a standpoint of frequency distribution, incidents blocking two lanes and incidents blocking three lanes are very similar; the distribution for the three-lane incidents is just shifted a bit to the right on the X-axis representing the longer RCTs associated with three-lane incidents. On average, for two-lane incidents the roadway was cleared 44 minutes sooner than for three-lane incidents. The partners could discuss the differences in clearing two-lane versus three-lane incidents. Perhaps there are incidents that block three roadway lanes that could be configured to only block two lanes, which might effectively reduce the overall roadway clearance times. The partners could set a goal to shift the RCT frequency distribution closer to that of two-lane incidents.

Incidents blocking four or more roadway lanes occur much less frequently; however, when they do occur, delays to motorists can last for hours. One thing that might help the Northville TIM partners develop roadway clearance strategies for these types of incidents is to pull the characteristics of the “worst” incidents from the TIM performance measurement database. For example, what was the injury severity associated with these incidents (how many injuries/fatalities)? Was a heavy vehicle involved in any of these incidents? What time of day did these incidents occur? Where (what roadway, which direction, at what location) did these incidents occur? Sitting down and discussing the details associated with these incidents, potentially conducting table top exercises, could help the partners develop strategies for reducing roadway clearance times.