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21st Century Operations Using 21st Century Technologies

Traffic Bottlenecks

Traffic Bottlenecks > Combating Bottlenecks

Combating Bottlenecks

Minnesota

Background: The success of these three projects lead to the implementation of the "Congestion Management Planning Study", an iterative process that has already sorted through 180, then 100, then 50, then finally 19 candidate projects via a screening process.

Bottleneck Projects:

A long-suffering need for an auxiliary lane was finally executed. Look what happened! I-394 WB from east of MN-100 to US-169 suffered from weaving and merging conflicts. Recent changes due to the installation of HOT lanes on I-394 made it imperative that the addition of an auxiliary lane be constructed. The project is since complete. An estimated 8:1 B/C ratio ensued; an increase in throughput by 4,600 veh's during peak periods daily was realized; and a decrease from 6.0 miles of congestion before, to 0.0 miles after was garnered. Also, a reduction in crash rates favors less property damage crashes too.

A 6-4-6 lane section of highway was made a continuous 6-lane section. I-94 in St. Paul, WB from Century Avenue and McKnight Road (near 3M HQ) was plagued by congestion for years due to its 4-lane section having 6-lanes up- and downstream. The 6-4-6 alignment was constricting entry and exit movements therein. Following $10.5M of construction for the missing 2-lanes, the now-6 lane continuous section experienced a 14:1 B/C ratio; 3,200 veh's of throughput were increased during peak periods; and anywhere from 4-5 miles of backups (depending on direction) were reduced to 2-4 miles.

Modified two sub-standard interchanges. TH-100 from 36th street to I-394 was a 4-lane section sandwiched between two 6-la sections. A prior Mn/DOT study found this section was exposed to congestion for the longest amount of time per day on the Twin Cities metropolitan freeway system. For the most part, a full third lane was added in each direction. (Short sections of shoulders were converted in some places for sake of congruency.) Additionally, a close-by diamond interchange was connected via C-D roads, reducing access points from 7 to 4. Through traffic now has a much improved ability to avoid weaving traffic through this stretch of on- and off-ramps past the city. The result yielded a (some say conservative!) 13:1 B/C ratio;  an increase of 14,400 veh's during peak periods daily; and backups of 5-6 miles (depending on direction) were reduced to 0.25 miles. Mn/Dot received an outpouring of positive public reaction, including one local newspaper's "public project of the year" award. Remarkably, this $7.1M project accomplished much the same result as a $138M project on a parallel freeway facility, I-494 from highway 5 to highway 55. Granted, the latter design/build project was closer to a total facility rehab, including noise walls and other costs, but the effect of practically eliminating long bottleneck queues was realized for a fraction of the cost on the former project.