Traffic in Honolulu is unbearable enough as it is. But transportation officials must surely realize by now that tinkering with roadwork during commuting hours — holiday or not — is a dicey gamble.

Let's hope Monday's slow journey westbound on the H-1 Freeway made that point crystal clear. Leeward-bound drivers found their afternoon drive from Downtown to Mililani extended to nearly three hours; workers could not complete Zipper Lane work in time because paint had not dried.

State Department of Transportation officials said they did not expect traffic on Monday's Martin Luther King Jr. holiday to be that busy. They had scheduled Zipper Lane repairs on a Monday holiday six times in three years; it had become standard procedure.

Not this time. Traffic was a nightmare, yet again frustrating O'ahu's drivers.

To its credit, the department was quick to acknowledge it had miscalculated. Opening and closing the Zipper Lane can take up to four hours in each direction. That doesn't leave much of a window to make needed repairs. The state is considering sliding the work into a Sunday evening; or splitting the work between two days may be the solution.

Whatever we do, let's think this one through.

"We don't want another repeat," said DOT spokesman Scott Ishikawa.

Good thinking. Neither do O'ahu's drivers.