District 9-0 SR 1021-002
This mile long rural corridor was identified as a high accident area due to the steep grade and two very sharp horizontal curves exacerbated by poor sight distance at its intersection with T-523. After identifying the environmentally sensitive areas and coordinating with PennDOT to determine the primary objectives and appropriate funding for construction, LDG developed a full range of alternatives from 3R to 55 MPH design criteria for improving the safety of the corridor. Matrices of the alternatives included construction costs, environmental impacts/mitigation, traffic control, utility relocations, R/W impacts, permits, and a list of pros/cons.
In addition to color plans and display boards, LDG displayed the project design files and presentation material via a laptop and overhead projector allowing attendees to actively interact throughout the alternatives presentation. This allowed stakeholders to view specific details of the designs, far more project information than could be presented on hard copies, and allowed for “right-sizing” which led to the selection of a preferred alternative a month earlier than scheduled. The selected alternative developed by LDG, a beefed up 3R design with curve widening, met the objectives of the project and reduced the construction length and cost by almost one-half from the more typical conservative PennDOT alignments based on conventional design criteria.
By flattening the curves, implementing curve widening, slightly re-aligning the roadway, and utilizing design exceptions, the safety objectives were met. The design speed for each of the two curves was improved by 15 MPH, sight distance was corrected at the intersection, and a potential new stream crossing was avoided.