Timing of traffic lights adjusted at Shipman Business Park intersection

The state Department of Transportation has offered more details regarding the installation of traffic signals at the intersection of Highway 11 and Kipimana Street — the entrance to Shipman Business Park — following observations conducted since the lights were activated in late October.

The new traffic lights caused congestion along the corridor in the days after they were activated.

According to the DOT, the signals were designed as a “continuous green-T intersection” to allow northbound traffic on Highway 11, or Volcano Road, to flow continuously while controlling southbound traffic and traffic heading into and out of Shipman Industrial Park.

This design reduces the potential for angle crashes, where one vehicle hits another at an angle, the department said, and makes traffic conditions at the intersection more predictable for cyclists and pedestrians that may be using the mixed-use shoulder.

Since the lights were installed, the DOT and Hawaii County Department of Public Works have adjusted the timing of the signals.

Adjustments include maximizing the length of green lights for Keaau-bound traffic on Highway 11 between 2-6 p.m. — green light times will be between 130 and 150 seconds for travelers headed toward Keaau — and decreasing the green light time on Kipimana Street to 15 seconds, from 35 seconds.

According to the DOT, additional observations first week in November showed an average delay of 5.5 minutes for Keaau-bound travelers on this stretch of Highway 11. DOT will continue to observe the intersection and make safety adjustments.