Northern Virginia Express Lanes Design Challenges and Solutions IBTTA Maintenance and Roadway Operations Workshop June 25, 2018
Virginia Express Lanes Overview 60 miles of managed lanes (4 projects) Long term DBFOM agreements with Virginia Department of Transportation 495 Express Lanes Opened in 2012 11 miles, 2 new HOT lanes in each direction New construction 95 Express Lanes Opened in 2014 29 miles, 2/3 reversible lanes HOV to HOT conversion 395 Express Lanes Under construction, target completion fall 2019 8 miles, 3 reversible lanes (1 new lane) HOV to HOT conversion 95 Fredericksburg Extension Financial close anticipated spring 2019 Target completion fall 2022 10 miles, 2 reversible lanes New construction 2
Express Lanes 101 How the Express Lanes work Dynamic pricing principles Contractually required to maintain 45 mph on 495 Express Lanes and 55 mph on 95 Express Lanes Toll prices are updated every 10 minutes to maintain free-flowing travel Toll prices are based on demand measured by road sensors providing real-time traffic volume and speed information Drivers see the toll price on signage twice prior to entering the Express Lanes HOV enforcement via Virginia State Police 3
495 Express Lanes Existing interchanges on 495 GP lanes (blue) are oversaturated, and processing additional traffic from Express Lanes at same location was not an option Arterial connections are often not suitable to build a new interchange due to cloverleaf configuration or closely spaced traffic signals Express Lanes interchanges were designed as new connections to overpass arterials (purple), which distributes traffic more evenly within the neighborhood and relieves congested GP interchanges 4 buffer separation of GP and Express Lanes instead of conventional shoulder and barrier design saved extensive right-of-way property takes, 350 homes, and millions of dollars SB Exp. Lanes NB Exp. Lanes 495 Route 123 GP Interchange Westpark Express Lanes Interchange 495 Route 267 GP Interchange Route 267 Express Lanes Interchange Jones Branch Express Lanes Interchange SB GP Lanes 4 Buffer with Channelizing Posts 495 NB GP Lanes Route 7 GP Interchange Route 7 Express Lanes Interchange 4
95 Express Lanes Space constraints within corridor limit shoulders to 2 and 10 Lane Use Control Signals (LUMS) provide mitigation for narrow (11 ) lanes and shoulders Variable Speed Limit Signs (VSLS) are used in conjunction with LUMS at ½ mile spacing Normal operational speed is 65 mph, but 55 mph is posted automatically when a lane is blocked 95 5
395 Express Lanes Major road network challenges: Transition on northbound 395 Express Lanes from 3 reversible to 2 lanes in each direction Traffic capacity limits on Eads Street off-ramp (single lane) from northbound 395 Express Lanes 1 2 3 395 Space constraints on Eads Street under 395 HOV Lanes bridge (2 lanes each direction including turns) Army Navy Drive Eads Street 6
395 Express Lanes Design challenges: AM operations would require 3 to 2 lane merge under existing configuration Space and cost constraints limited the ability to expand roadway Traffic bottlenecks would be anticipated at critical northern terminus 7
395 Express Lanes Design solution: Extend reversible section further north by approximately 2,000 feet to Eads Street Eliminates 3 lanes to 2 lanes transition (establishes 3 lanes to 3 lanes at this location) Provides consistency of capacity at northern terminus to promote smooth traffic flow conditions 8
395 Express Lanes Design challenges: AM operations would require all Eads Street traffic to use single off-ramp (#2) Traffic queues could be lengthy at offramp and Eads Street signal (#2) Space and cost constraints limited the ability to expand Eads Street lane capacity (#3) 9
395 Express Lanes Design solution: Extend reversible section north by 2,000 feet to Eads Street and make both ramps reversible (#2) Splits heavy traffic demands into two parts that use different ramps and intersections altogether (#2) Eliminates need for additional space on Eads Street (#3) 10
395 Express Lanes Dual reversible ramps Dual reversible ramps are provided to address a number of design concerns: Provides maximum traffic capacity by dividing heavy Eads movements between two ramps Maximizes use of existing infrastructure, no new bridges or lane widening required Creates additional safety layer with introduction of new gate groups (off-page right) 11
Thank you for time. Questions?