Longtime Coronadans can remember the days when they preferred to drive the lanes close to the edge of the Coronado Bridge. Sure, they were closer to “a long way down” but it was better than driving in the fast lane where the only thing separating them from a potential oncoming collision was a strip of orange cones.

That changed in 1993 when one of the biggest “zippers” imaginable was installed. The “zipper” features a row of 32-inch high concrete bricks, each weighing approximately 1,400 pounds, connected by metal pins. Each day the zipper is zipped up and down to move a lane of traffic, thus helping ease congestion for Coronado’s huge ebb and flow of cars coming onto the island in the morning and flowing back out each afternoon. The added bonus was that oncoming collisions, often resulting in fatalities and closing the bridge for hours, became a thing of the past.

The zipper also allowed for more charity runs across the bridge; today, races can occur on one side of the barrier while low weekend traffic can be easily accommodated on the other.

Two blue vehicles which move the heavy concrete prongs are dubbed Stu and Harvey, in honor of the retired CalTrans District Supervisor Stuart Harvey who discovered a similar system in New Zealand.

Stu and Harvey make two sweeps across the bridge daily, adding a third land for the heavy westbound traffic coming onto the island in the morning, and zipping the barriers back to allow three lanes of outgoing traffic in the early afternoon.

Before the zipper, the maintenance crew would have to set out cones to accomplish the lane changes. It was dangerous work for the crew and not all that safe for drivers.

When in one of the vehicles, CalTrans worker Gerald Browning relies on an auto guidance to steer, while he focuses on adjusting the tension and compression of the zipper wall because the wall would be to hard to pick up if too tense, and “would kink and pull apart” if too loose. All eight members of the bridge maintenance crew know how to operate the zipper vehicles, and it takes three crew members to move the barrier.

After 16 years of working on the bridge, Browning still enjoys seeing people “waving and smiling” at him as they pass.