Traffic Signal Retimed to Alleviate Congestion at Busy Intersection

In an effort to improve north and southbound approaches to a busy intersection connecting Alexandria and Arlington, the traffic signal at the corner of Mt. Vernon Avenue and South Glebe Road was recently retimed.

The cycle length of the signal was reduced in May by Arlington County to aid approaches to both Mt. Vernon Avenue and Arlington Ridge Road, especially in the peak morning periods.

Traffic routinely backs up on Mt. Vernon Avenue near the intersection in Arlandria during peak hours because vehicles have a hard time making the left turn onto Glebe Road.

The reduced cycle length does not provide the dramatic improvement that could be accomplished with the addition of turn lanes, but it does offer short-term mitigation, according to a memo from the Arlington Department of Transportation and the Alexandria Department of Transportation and Environmental Resources.

Hopes of adding a left-hand turn lane from Mt. Vernon Avenue onto Glebe Road remain slim because of constraints within the intersection, the memo said. 

According to the memo, the intersection is too narrow to construct turn lanes within the existing right-of-way. Upgrading and expanding the intersection with a turn lane would require the use of parkland along Four Mile Run. Such a proposal would present “numerous challenges,” the memo said.