The Detroit-Windsor tunnel carries 17% of all vehicular traffic between the province of Ontario and the United States. That's about 4.4 million vehicles and 8.7 million travelers annually.
The increased security implemented after the September 11th attacks caused a dramatic increase in traffic congestion. Ed Williams of PMC used SIMUL8 to investigate the changes required to alleviate this.
The September 11th terrorist attacks in 2001 caused the United States to tighten security at all border entry points. This resulted in a dramatic increase in traffic congestion and become costly to commercial enterprises.
Long delays also infuriated the traveling public and resulted in emergency vehicle access being blocked in Windsor due to long lines of vehicles on Windsor’s thoroughfares awaiting access to the tunnel.
A solution which allowed the increased security to remain whilst decreasing traffic had to be found.
Two scenarios were tested using SIMUL8: (1) Five tollbooths open in Windsor and five customs booths open in Detroit; (2) Five tollbooths open in Windsor and six customs booths open in Detroit.
Scenario 1 was adequate for 5AM-7AM. For 7AM-9AM, scenario 2 was far superior. The closure of one booth on the Detroit side doubled the time in system and multiplied by more than seven times, the probability that the tunnel will be closed because no vehicles queuing in the tunnel is allowed.
The tunnel management began to use these results immediately to alleviate the traffic congestion. The results of this study were a significantly contributing factor to the United States government’s decision to add 97 customs officers to Michigan’s border crossings to Canada.