About this Project
As an on-call highway engineer for MaineDOT, FST was selected to provide design for the reconstruction of the I-295 Exit 15 interchange in Yarmouth. The project involved upgrading the existing ramps, adding a new ramp, and providing a park and ride facility. These improvements were necessary because the existing northbound off-ramp utilized a sharp curve immediately after departing from the interstate, the existing southbound on ramp provided substandard merging distance and sight lines with southbound traffic on I-295, and the traveling public desired a northbound on-ramp. The reconfiguration of the interchange also created an opportunity to provide a park and ride facility to assist commuters and improve traffic flow on US-1 (15,000 AADT) through the interchange.
In preliminary and final design, FST created an electronic, three-dimensional model of the project using Bentley’s Microstation and InRoads. Design services included realignment of ramps, site development for a park and ride facility, stormwater drainage including bio-retention ponds (a first for MaineDOT), highway lighting for the ramps, signing and pavement markings, a soil nail retaining wall underneath an existing bridge to accommodate a safer ramp configuration, 37,000 cubic yards of rock blasting and excavation (design coordinated with DOT’s geotechnical engineer), bicycle lanes, and construction staging concepts. Design included coordination with the public and utilities through field meetings, correspondence, and hearings.
FST provided construction assistance for MaineDOT. Construction was completed on schedule, and the new interchange was fully open in 2013.
Owner: Maine Department of Transportation
Location: Yarmouth, Maine
Highlights: FST's design provided improvements to Route 1, including new pavement markings, signing and intersection realignments. In addition, the design involved the layout of an alternating merge area to accommodate predicted unbalanced traffic volumes where the majority of traffic is in the outside lane. The configuration in one of only two locations where Maine DOT has used this particular innovative approach.