“A two-way left-turn lane (TWLTL) is a street configuration that provides a center lane for left turning vehicles traveling in either direction. A TWLTL removes left turning vehicles from the through lanes and allows vehicles to wait in the center lane until a safe gap in oncoming traffic is available before turning left.” Source: https://www.mass.gov/doc/two-way-left-turn-lanes-informational-guide/download
Uses: • Driveway entrances or side streets are spaced too closely to place dedicated left turn lanes • Heavy volumes of left-turning traffic can cause congestion along the main roadway Source: https://iowadot.gov/design/dmanual/06c-06.pdf
Roadway with TWLTL
Multilane Roadway without Left Turn Lanes Left-Turning Vehicle
Typical Section of a Roadway with One Travel Lane in Each Direction and Two Way Left Turn Lane Source: streetmix.net
Reduced Delay for Through Vehicles Reduced Potential for Rear End and Sideswipe Collisions
Potential for Rear End Collisions Potential for Sideswipe Collisions Increased Separation Between Opposing Lanes of Traffic Reduced Delay for Vehicles Turning from the Minor Street
Two Way Left Turn Lane (TWLTL)
A TWLTL provides increased clarity during emergencies and allows emergency services vehicles to bypass stopped traffic, if necessary. https://www.mass.gov/doc/two-way-left-turn-lanes-informational-guide/download