Would green arrows point to less congestion?

Q: The development growth in the Wescosville area and the arrival of the Route 222 Bypass have produced a bottleneck at the intersection of Hamilton Boulevard and Brookside Road. The entrances and exits at the nearby businesses further complicate matters, and continued growth is expected along Hamilton. Surprisingly, there is only one right-turn green arrow at this intersection, for northbound Brookside traffic turning right onto Hamilton. The other turning lanes do not have green arrows, and rush-hour congestion results from traffic waiting to turn in either direction onto Hamilton. Is there talk about putting more turning arrows at the intersection to alleviate the traffic jams?

— Rick Kline, Lower Macungie Township

A: There's been no talk about adding left- or right-turn green arrows to this overburdened intersection up to now, according to PennDOT and Lower Macungie Township officials. So let's initiate that discussion.

A left-turn green arrow guides traffic at this intersection from westbound Hamilton to Brookside, and a right-turn arrow applies for northbound Brookside onto Hamilton. The two illuminate simultaneously, working together, as the turning movements do not conflict. Unfortunately, this phase lasts for only about seven seconds. They are the only two green arrows at the intersection.

In first gear, my impression was that left- and right-turn arrows for other directions might help ease the traffic burden to some degree, but that the effect would be limited. For starters, I suggested left-turn arrows for Brookside traffic in both directions.

"I do not know if they would help the intersection or hinder it," PennDOT traffic-signals manager Tom Walter wrote in an email. "They would definitely help the Brookside left-turners, but then the time to accommodate the left-turn signalization would have to come from other movements within the intersection, which would most likely cause more congestion."

We're up against the familiar reality facing traffic-signal phasing adjustments: Any extra green time granted to traffic in one direction must be stolen from the conflicting traffic's green phase. Walter repeated a caution he's issued on previous journeys: "Remember that there are only 60 seconds in a minute to divide up between all these movements." Traffic engineers can't give more green time to frustrated motorists in one direction without jacking up the frustration of those in the opposite direction.

At this intersection, left-turn phases for both directions on Brookside would rob green time from the straight-through traffic on Brookside, or from Hamilton traffic. From my limited observations, the dominant Brookside movement consists of northbound traffic turning right onto Hamilton, which already gets a green-arrow phase, plus the benefit of right-on-red, though that is limited because conflicting traffic is almost constant at rush periods.

For traffic on eastbound Hamilton coming from any leg of the intersection, a problem is posed by the immediate appearance of another traffic signal, at Minesite/Schantz roads, only 500 feet — less than one-tenth mile — to the east. I thought synchronization of the signals at the two intersections might help, but Walter said they're already synchronized. A tweak might be in order, but again, it would be of only minimal help. The exit from the Wawa market onto Hamilton, which lies between the two signals, further burdens the boulevard.

I think it's a classic case of traffic volume overwhelming the capacity of the signals, regardless of programming refinement. Whenever it's stacked up in either direction on Brookside, there's also a solid line of traffic on Hamilton between Brookside and Minesite/Schantz. Often, motorists can't take advantage of portions of their green phases because the line to Minesite/Schantz stacks back to Brookside. Motorists who block the intersection out of frustration don't help matters.

Lower Macungie Public Works Director Dennis Hinkel said people have complained that the left-turn arrow from westbound Hamilton to Brookside is too short, allowing too few vehicles through. But it's unlikely PennDOT would approve additional time for that phase, he said, because traffic engineers specifically intend to discourage that movement. Instead, the phasing invites westbound motorists headed for southbound Brookside to use the Bypass to the Brookside off-ramp, thus staying off Hamilton.

"It's specifically designed to keep traffic off of Hamilton," Hinkel said, noting that the green phase for southbound through traffic at Hamilton is lengthy, allowing many cars to pass. Though quite a few businesses are on the brief two-way stretch of Brookside north of Hamilton, the northbound direction dead-ends after two-tenths of a mile, where the road meets the southbound-only off-ramp. Most southbound traffic on that side of Hamilton should be coming from the Bypass.

I think it's pretty hopeless in terms of re-phasing or green arrows, Rick. Hinkel said some unspecified intersection improvements are anticipated at Minesite in the next few years, which might help to some degree, but in the same breath he mentioned the continued development that's expected along the Hamilton corridor, and … well, you know the drill.

Hinkel said the Bypass generally eased Hamilton Boulevard traffic congestion, particularly culling a lot of the truck traffic, as expected after it opened fully in September 2007, and I agree. But the slowdowns could be creeping back onto the boulevard as development grows and savvy motorists find the routes most suitable to specific trips. I theorize that the absurdly slow 45 mph speed limit on the Bypass promotes that process to some degree.

Traffic-signal questions, led by calls for green arrows or longer green phases, are so numerous that I hesitate to use them in the column for fear of highlighting some at the expense of others. This one glowed in the headlights in part because I recently had to use this intersection more than usual, and wondered whether the benefits of the Bypass might be wearing off already. A similar phenomenon followed the completion of Interstate 78 in November 1989: It was expected that the new highway would take most of the tractor-trailer traffic off Route 22, and it did — for a time.

Could the Route 222 Bypass already be losing speed in luring traffic away from Hamilton Boulevard? How long till Hamilton gridlock returns if much of the anticipated retail development steers into the passing lane, particularly if the economy improves? Describe for me the view through your windshields, fellow warriors.

Road Warrior appears Mondays and Fridays, and the Warrior blogs at mcall.com. Email questions about roadways, traffic and transportation, with your name and the municipality where you live, to hartzell@mcall.com, or write to Road Warrior, Box 1260, Allentown, PA 18105-1260.





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