Oct 18, 2013 12:20 AM by Stefanie Boe
TUCSON - Get ready for the next indirect left turn to get switched on in Tucson. Drivers on eastbound and westbound Grant Road at Oracle will see yellow flashing turn signals starting Friday to alert them to the changeover to the new indirect left turn function that will go fully into effect starting at 6 a.m. Tuesday, Oct. 22.
The City of Tucson intersection project at Oracle and Grant is the first segment of the larger Grant Road, Oracle to Swan, roadway improvement project in the Regional Transportation Authority's 20-year, $2.1 billion regional transportation plan.
Pima County opened an indirect left intersection at Oracle and Ina in early September. The county reports seeing increased efficiencies.
How does it work?
Traffic flows through the intersections, eastbound and westbound, and once through the intersections, the left lane traffic can merge into a left turn lane. The left turn lane is managed by a traffic signal. When the signal is green, traffic can make a U-turn, enter the right lane and return to the intersection, where they can make a right turn to head north or south.
Simply, go through, make a U and then right at the light.
Traffic using the indirect left turn intersections is prohibited from turning left at the intersection. Emergency vehicles are the exception.
According to the city's news release indirect left turn intersections are safer, faster and save on gas:
• They reduce total car crashes and injury crashes
• They shorten crossing distance for pedestrians
• They provide "bike spots" for safer bicycle turns
• They allow room for turns made by buses and semi-trucks
• They improve overall efficiency for all movements through the intersection
• They reduce fuel consumption with vehicles idling less at the intersection
The Grant Road project includes a "bike spot" that helps direct bicycle traffic through the intersection.
According to the Federal Highway Administration, indirect left turns help reduce crashes, improve congestion and add capacity with a 15 percent to 20 percent gain. Crashes decline by 20 percent on average and 35 percent if the indirect left turn is signalized.