Hand in hand with the work on and attention to the Harrisburg Pike corridor that accompanies the Crossings project, additional ripple effect has included the formation of the Harrisburg Pike Land Use and Transportation Study Steering Committee, which is working to improve the overall carrying capacity of the Harrisburg Pike corridor and enhance safety for all users. This multidisciplinary, cross functional committee carries the torch to continued improvement and use of this important corridor and gateway into the City of Lancaster. Click here for the steering committee's report unveiled in July 2008 entitled Moving Smarter: Harrisburg Pike Transportation and Land Use Study.

“Unclogging an Artery” - click to view a .pdf of a Lancaster New Era article by Tim Mekeel, included here with permission. 

Route 30/Harrisburg Pike Interchange - click to view a .pdf of the existing Route 30/Harrisburg Pike Interchange superimposed with a schematic of a single-point urban interchange.
 

Advantages of a single-point urban interchange

Roadway improvements include plans to modify the existing Route 30/Harrisburg Pike Interchange from its current configuration (a diamond interchange) to a single-point urban interchange (SPUI).

Current delays with the diamond interchange configuration
In the current configuration, the most problematic delays occur during the four left-turn movements. Each of these left turn movements happens during a separate green phase, and the amount of green time for the left turn phases must be short enough so that the vehicles served during one signal cycle can be stored on the bridge between the two signalized intersections. 

The queues for the left turn movements cannot be cleared during one green phase, and the eastbound left turn movement from Harrisburg Pike onto Route 30 Eastbound creates a queue which extends through the signals at the Route 30 West Ramps and the Park City Driveway. 

As the queue extends through these intersections, the left turns from the Route 30 West Off-ramp and the Park City driveway cannot perform these movements safely during their respective green phases, resulting in gridlock.  The gridlock conditions on Harrisburg Pike result in queues on the off-ramps, which often back up into the vicinity of the Route 30 mainline.

SPUI allows opposing left-hand turn movements to occur at the same time
The most significant advantage of a SPUI is that the four left-turn movements which cause the operational problems at a diamond interchange all occur at a single, signalized intersection, and the opposing left turns can occur simultaneously.  The SPUI can significantly reduce delays by reducing the number of traffic signal phases from four to three, and it does not require additional right-of-way. The SPUI interchange is expected to reduce delay at this interchange by an average of 65% during the peak traffic periods. Since the SPUI signalized intersection will be located above Route 30, it will increase the spacing between the adjacent signals at Park City and Toys-R-Us, which will help eliminate the gridlock which occurs today along Harrisburg Pike in the vicinity of the Crossings site.