Slip Lane Reduction At Busy Intersection Approved In Alexandria

ALEXANDRIA, VA — A slip lane reduction at an Old Town intersection with busy traffic and safety concerns was endorsed by the Alexandria Traffic and Parking Board Monday.

The slip lane change will affect the eastbound Duke Street to southbound South Henry Street right turn option. The board approved reducing the slip lane from two lanes to one. In addition, the board endorsed no-turn-on-red restrictions at the Duke Street intersections with South Patrick Street and South Henry Street.

The roadway changes are part of a larger project at the two Duke Street intersections. Grant funding helped the city conduct safety audits at the intersections, which led to conceptual designs for improvements. Along with the slip lane change and right turn restrictions, the city will look to add leading pedestrian intervals to give crossing pedestrians a head start. Other improvements proposed for the intersections are curb extensions, increased lighting and turning painted medians into planted medians.

According to Alex Carroll, Complete Streets program manager for the City of Alexandria, the city could seek grant funding for design detailed design and construction of more costly or complex improvements, including curb extensions, planted median, slip lane geometric changes, signal improvements and street lighting upgrades.

The intersections were identified as high-crash intersections as part of the city's 2022 citywide crash analysis update. According to the city, over 75 crashes happened at the Duke Street intersections with South Patrick and South Henry Streets from 2015 to 2022. Most of the crashes were attributed to rear-end collisions, angle or sideswipes. Four of the crashes involved pedestrians, and three crashes resulted in severe injury. Alexandria has a Vision Zero goal to eliminate fatalities and severe injuries from crashes by 2028.

"When we looked at the crash narratives, what we found were some pretty common themes which included a lot of driver behavior issues such as distraction and impairment, but also speeding and failure to yield or stop," Carroll told the board. "So as we were going into this project, these are factors that we had in the back of our mind to try to identify countermeasures for understanding that some of it is going to be driver behavior, but then we can dictate some of that behavior by the roadway design that we develop."

A spring 2023 resident survey with over 340 responses found 67 percent said South Henry Street (the location of the slip lane) is unsafe or very unsafe, and 47 percent said the same about South Patrick Street. Top concerns identified in the survey were speeding, unsafe turns, disregarding signs and signals, and blocking the intersection.

Even though the slip lane from Duke to South Henry Street has a traffic signal, Carroll said drivers may not be able to see the traffic signal, and pedestrians face a risk when crossing.

"It can still be really difficult for people walking across there because of the high-turning volumes, people turning right on red, higher speeds, things like that," said Carroll.

Some members of the community spoke in support of eliminating the slip lane entirely.

Mike Doyle of the Alexandria Families for Safe Streets, said some of the organization's members avoid the intersection entirely because of the safety risk.

"We think it needs to be rethought more dramatically and more out of the box and eliminate these [pedestrian] conflicts," said Doyle.

Steve Malone, president of the Old Town Civic Association, also supports eliminating the slip lane entirely.

"If they can't be eliminated, I think eliminating one of the two is definitely an improvement," said Malone.

City staff considered two options for the slip lane, both with a reduction from two lanes to one. The option recommended by staff was to remove the signal and implement a no-turn-on-red restriction. The alternative not recommended by staff was removing the signal and installing a rapid flashing beacon pedestrian signal and raised crosswalk.

The slip lane change could increase traffic queuing by 30 seconds in the evening peak travel period, according to Carroll. She noted most cars use the right slip lane, and the left slip lane only holds about seven to eight cars. Little traffic impact is expected at the South Patrick Street and Duke Street intersection, although existing delays could be addressed by planned signal timing changes on Duke Street.