Bus strike zaps zip from high-speed lane
By Mike Leidemann
Advertiser Transportation Writer
The number of cars using the H-1 zipper lane increased 58 percent at the start of O'ahu's bus strike, but many of those drivers ended up traveling slower than cars in regular lanes, according to Department of Transportation statistics released yesterday.
The figures also show that the morning rush hour from Central and Leeward O'ahu is starting earlier and lasting longer than before the strike, but drivers may be reverting to old habits, adding to congestion in recent days.
The data, taken from a new computer reporting system that tracks the number and speed of cars on the H-1 near Halawa interchange, provide the first statistical glimpse at how the 2 1/2-week-old strike has affected traffic patterns across O'ahu.
"We're still trying to analyze all the data to see what other changes have occurred," said DOT spokesman Scott Ishikawa.
On Aug. 26, the first day of a strike by more than 1,300 O'ahu Transit Services workers, 4,710 cars used the zipper lane, which runs from the Manager's Drive overpass to Ke'ehi interchange.
That was up from a typical midweek use of about 3,000 cars.
Surprisingly, though, the total number of eastbound cars passing the Halawa checkpoint during the strike's first 24 hours did not increase as much as some engineers had expected. In all, 71,403 eastbound cars were reported, an increase of 2.4 percent over the number recorded on a similar Tuesday in April.
Transportation planners hoped that opening the zipper lane to cars with two or more occupants and extending its working hours would help thousands of daily suburban commuters. When in full operation, city buses serve an average of 240,000 passenger boardings each day.
While the plan lured many drivers into the zipper lane, it also had an unexpected consequence — a slowdown in traffic speeds — in the early days of the strike.
While cars on the rest of the freeway maintained speeds of 50 mph to 60 mph while passing Halawa throughout the first morning, drivers in the zipper lane were poking along at under 25 mph between 7 a.m. and 8 a.m., near the peak of the rush hour.
The statistics didn't surprise Mililani resident Richard Poirier, who said he saw the changes in the freeway traffic flow right after the strike began.
"The zipper lane is designed to be an incentive for those with three or more people in the car, not just a way to increase the highway capacity," he said. "When they opened it up to more cars, of course it was going to slow down."
"One theory is that all the extra cars slowed down traffic in the lane," Ishikawa said. "Another theory is that there were a few slow drivers holding up the rest of the cars. We're trying to figure out if the extra cars clogged the zipper lane, which is supposed to get you there quicker."
Use of the zipper lane dropped somewhat a few days after the start of the strike, and that has helped increase average speeds, Ishikawa said. On Tuesday and yesterday, recorded speeds on the zipper lane never fell below 44 mph, and the number of cars using the lane has remained around 4,000 — a 36 percent increase over pre-strike figures.
The Transportation Department has not yet decided whether the zipper lane will remain open to vehicles with two or more occupants when the bus strike ends, Ishikawa said. Normally, cars must have at least three occupants to use the lane.
The zipper lane was created in 1998, using movable concrete barriers to set off two 'ewa-bound H-1 lanes for town-bound traffic.
The new DOT figures mirror what transportation engineers have observed since the strike began: traffic patterns that shift almost every day as motorists try to find the best ways to get around.
"It's like water seeking its own level," city Transportation Services Director Cheryl Soon said yesterday.
In the first days without buses on the road, traffic began to peak on the H-1 about 5:15 a.m., with 2,000 cars passing near the Halawa interchange. Before the strike, the 2,000-car level was not reached until about 5:45 a.m., according to the DOT statistics.
In the last week, however, drivers have begun starting later again, Soon said.
"Congestion is getting worse this week. We're still telling people they'll have a better travel time if they leave earlier."
Soon said recent education and enforcement efforts had helped cut down on drivers crowding intersections and causing traffic backups.
"We were focusing on giving more green time (on traffic signals) to the main streets, but side streets were getting more and more crowded, and that's when the intersection started to back up with people trying to squeeze through," she said.
"It was definitely getting tighter, but we got on top of the problem right away," with more police officers handing out warnings and tickets in intersections.
