You may not have noticed, but driving on Cedar Crest Boulevard usually is taking less time, even at the busiest times of day on the heavily-traveled highway.

Cedar Crest is one of the most congested major roads in the Lehigh Valley, according to staffers at the Lehigh Valley Planning Commission.

Last year the state Department of Transportation made improvements at most of the 15 signaled intersections on a more than five-mile stretch of the road, between Chestnut Street in Emmaus and Tilghman Street on the Allentown-South Whitehall boundary.

Those improvements included new signal modifications, retiming lights and adding uninterruptible power supplies, so traffic lights continue to work when the electricity goes out, explained Michael Donchez, a senior transportation planner at the planning commission.

Donchez said PennDOT has a Congested Corridor Improvement Program, which identifies roads that can benefit from such “low cost, quick turn around” improvements to aid in the movement of traffic. The goal of that program is a 20 percent reduction in peak hour travel times in an improved corridor.

A planning commission study shows that 20 percent goal has not quite been met by PennDOT’s intersection improvements. Travel times improved by more than 14 percent for northbound traffic and by more than 11 percent for southbound travel at peak volume times in late afternoon, the busiest time of day on that road.

Donchez said the study determined PennDOT’s intersection improvements increased speeds by 3 to 4 miles an hour in the corridor.

A draft report of the “post-improvement review” on the corridor was presented and approved at Wednesday morning’s meeting of the Lehigh Valley Transportation Study’s coordinating committee.

In addition to travel speeds, the study also looked at stop delay --“the amount of time you are sitting there motionless in your vehicle,” explained Donchez. PennDOT improved stop delays in the p.m. peak hour by nearly 25 percent for northbound traffic and by nearly 21 percent for southbound traffic.

Southbound traffic at morning peak hours actually has experienced a more than 10 percent increased delay, but the report states “delay in the corridor overall decreased in the morning peak…the overall net impact was one of shorter durations of delay within the corridor.”

Donchez said Cedar Crest was the highest priority congested corridor in Lehigh or Northampton counties that had not yet been studied by the planning commission. He said its initial study was done before PennDOT made the intersection improvements to learn “pre-improvement operating conditions.” After those improvements were implemented, the planning commission went back to the Cedar Crest corridor to gather more data for comparison.

The planning commission’s review reports daily traffic volumes along the corridor range from 10,100 vehicles in the southern portion of Cedar Crest to 26,100 vehicles around the I-78 interchange. By 2030, daily traffic volume is projected to increase to 16,900 vehicles in the southern portion and 34,800 vehicles at I-78.

The report recommends that PennDOT and Allentown should work to coordinate and re-time traffic signals as a cost-effective way to continue to improve traffic flow on Cedar Crest.