This project converted the inside shoulder of northbound I-495 to a travel lane. Volkert provided civil and traffic design and quality assurance for the Virginia Department of Transportation project. Volkert also developed the traffic management plan to keep all travel lanes open during construction.
Civil design improvements included cross-slope correction to meet the 70-mph design speed, static signage, pavement markings, as well as mill and overlay. The design also included pavement joint repairs, pier protection upgrades at overpasses, median barrier modifications for increased safety, and drainage upgrades.
Traffic engineering staff developed the most stringent Type C, Category V Traffic Management Plan to maintain traffic on all lanes during the three phases of construction, as well as provide for Maintenance of Traffic.
Additional design elements included the development of Intelligent Transportation System architecture to connect with existing VDOT infrastructure and communicate with the client’s Transportation Management Center. This included overhead signals with variable lane control indicators: green “open” arrows, amber “merge” arrows, and red “closed” Xs to direct motorists.
CCTV cameras were installed to monitor the shoulder lane, along with several pan-tilt cameras that monitor the entire highway section. Dynamic message signs have been installed to alert motorists of any traffic incidents or delays.