Zipper Merge Technique Recommended For Bay Bridge Construction

ANNE ARUNDEL COUNTY, MD — Construction begins on the Chesapeake Bay Bridge Tuesday, Sept. 24, and there is one driving technique that will help alleviate a considerable amount of the stress that accompanies traveling through a construction zone, especially one as busy as the bridge will be.

AAA officials explained that if everyone utilized what's called the "zipper merge," there would be fewer traffic jams, less road rage and improved safety in work zones. He noted that it may seem counter-intuitive, but it really does work, reducing delays in work zones by up to 40 percent, studies reveal.

“Using the ‘zipper merge’ technique when it is safe to do so in construction zones will keep traffic moving and help reduce crashes and congestion,” said Kurt E. Gray, director of driver training for AAA Mid-Atlantic. “When it comes to merging in heavy traffic conditions, most drivers do it wrong by merging too early. Study after study shows the ‘zipper merge’ is the safest and most efficient way to merge in work zones and heavy traffic. To do so, use all lanes fully until you reach the end of the lane, then alternate into the open lane. It does take some cooperation, but it maximizes road space and helps keep things moving.”

Any motorist's commute using the Chesapeake Bay Bridge will become more complicated once construction begins “due to no two-way traffic operations,” beginning Sept. 30. During September and October, area motorists must brace themselves for ongoing construction and traffic alerts along at least 18 major construction sites in Northern Virginia, nine major construction projects in Prince George’s County, eight active construction projects on bridges and roads in Montgomery County and re-pavement projects along 88 miles of roadway in the District of Columbia, the AAA shared. Work zones are the “second largest contributor” to non-recurring delay congestion in the nation and the “speed-flow-delay paradox” across the Washington metro area.

“Some skeptics say good luck trying to ‘teach longtime drivers new tricks.’ That is to say, convincing motorists to change their deep-dyed habits of merging early. Though a tad controversial, the overarching goal of the ‘dynamic lane change’ or the ‘late merge’ technique is improving traffic flow and enhancing traffic safety in work zones and heavy traffic,” said John B. Townsend II, AAA Mid-Atlantic’s manager of public and government affairs. “Research tells us 50 percent or more of all traffic delays across the Washington metro area is ‘due to non-recurring incidents,’ ranging ‘from a flat tire to an overturned hazardous material truck (25 percent of congestion), weather (15 percent of congestion), and work zones (10 percent of congestion).’”

Zipper merging “can reduce delays by up to 40 percent in heavily congested areas,” according to studies conducted by the Colorado Department of Transportation. In addition to enhancing work zone safety, the “zipper merge” method, which derives its name from “teeth in a zipper,” also promises to “ease traffic and make driving through work zones go quicker.” Drivers using the “zipper merge” method should continue to occupy all lanes until they reach the “taper point” in the work zone and then take turns merging into the open lane in an orderly and alternating fashion. However, if there is no bottleneck and an early merge makes sense, feel free to do so, Townsend II said.

"Drive consistently. Don’t rush ahead, only to slam on your brakes later," he explained.

Here are a few additional tips from AAA for merging in work zones.

• Slow down and obey the speed limit. Speed was a contributing factor in 29 percent of work zone deaths in 2017.
• Pay attention. Conditions could change quickly. Plus, 25 percent of fatal work zone crashes are rear-end crashes.
• Give heavy vehicles and equipment a wide berth and room to adjust to conditions.
• Move over, if possible, for workers.
• When ready to move over, signal your intent and use the zipper merge approach in an alternating fashion.
• If, however, a lane closure is due to a crash or breakdown, reduce your speed and move over as soon as possible to avoid endangering emergency workers and/or tow truck operators.
• Drop it, the phone, that is, and drive.