Main Street (US287) and Ken Pratt Blvd. (SH119) Intersection Improvements
Project Background: As the busiest intersection in Longmont, the Ken Pratt/Main intersection experiences unacceptable levels of delay for several movements during the weekday peak morning and evening hours. In particular, the heavy eastbound traffic in the PM peak hour results in excessive queuing west on Ken Pratt Boulevard. Quite often, the queue extends past S. Pratt Parkway. These lengthy queues and heavy congestion have led to an increase in rear-end accidents for eastbound traffic. Additionally, other movements are observed to experience high delays during certain peak hours. The objective of this project is to identify and construct needed improvements to add capacity and improve safety for both the immediate and long-term scenarios.
The Main Street (US 287) and Ken Pratt Blvd. (SH 119) Intersection Improvement project is a local agency project between the City of Longmont and the Colorado Department of Transportation (Region 4). This project is identified in the City's Capital Improvement Program as T-109. Funding for this project will be a combination of CDOT FASTER and City of Longmont funds.
Recommended Improvements: A list of potential improvements was analyzed during the preliminary design phase to identify which improvements would provide the greatest benefits to the public by increasing safety and reducing delay. For the Ken Pratt/Main intersection, the recommended improvements include an additional lane in the eastbound, westbound and southbound directions. Additionally, the construction of right-turn lanes for the eastbound and westbound directions was recommended at the Ken Pratt/S. Pratt intersection.
Project Status: The City’s consultant is finalizing the design and preparing final plans and specifications for proposed improvements. The design has identified several property interests that will need to be acquired before the construction can begin. The City is currently negotiating with the adjacent property owners. Once the necessary right-of-way/easements have been secured, the City will bid the work for construction. The construction will be broken into two separate phases/projects. The first phase will include the construction of a concrete box culvert along the south side of Ken Pratt Boulevard between S. Pratt Parkway and S. Main Street. This culvert will replace the existing open ditch and convey storm drainage runoff under the widened road/sidewalk. The second phase of construction will consist of roadway widening and intersection improvements at Ken Pratt/Main and Ken Pratt/S. Pratt. The first phase of construction (box culvert) is currently scheduled to begin in Spring 2014, depending on ROW acquisition.
Attached is an "Executive Summary" of the traffic analysis study that was completed by the City's design consultants as part of the initial design analysis.
If you have questions about this project, please contact Micah Zogorski at (303) 651-8594.
For comparison purposes, the City's consultant prepared a traffic simulation video that depicts the traffic in the PM peak hour. The first clip shows the current traffic in the PM peak hour (note the heavy eastbound and northbound traffic). The second clip is the current traffic volumes with the proposed improvements. As depicted in the video, the proposed improvements provide significant improvements to the overall operation of this intersection, especially for the eastbound through movement. The additional lane capacity for the eastbound direction also allows some adjustment to the signal timing and provide more green time for the southbound left turn movement.