Traffic studies under way near new bus barn site

MAT-SU — Three school buses slowed and pulled into a turn pocket Wednesday afternoon to stage for a left turn off the Palmer-Wasilla Highway and onto Hyer Spur Road.

It's new traffic for the neighborhood, brought to Hyer Spur by First Student, a British company that was awarded the transportation contract for the Matanuska-Susitna Borough School District last spring. Part of First Student's plan is operating a single bus barn for its fleet of about 160 buses.

Tom Adams, an engineer from Lounsbury and Associates, stands on a stretch of bike path at the intersection with a clipboard, stopwatch and compact camera. Adams juggles his tools deftly, checking times, noting the times on a chart, and occasionally pausing to snap a photo.

The data Adams is gathering will be used in traffic analysis for the intersection. Stopwatches, spread sheets and arcane acronyms such as LOS (level of service) are the bread and butter of traffic analysis.

LOS is a way of describing how well an intersection accommodates traffic. An LOS score ranges from "A" to "F," just like a student's report card. An LOS might be specific to one traffic movement, say, a left turn onto the highway from Hyer Spur Road, which currently scores a "C," according to a report from Lounsbury Engineers.

The analysis also involves a fair amount of research into the intersection's history, and naturally, more than one person. Adams has a coworker stationed in a pickup truck nearby who is gathering overall traffic data while he times the school buses.

"Because of the volume of traffic, it takes someone dedicated just to do that, while I was using the stopwatch on the buses," Adams said.

The history of the intersection is drawn from numbers provided by the Alaska Department of Transportation (DOT). DOT also has future projections for the highway, but the curves on those charts will likely steepen with the addition of school bus traffic.

The bus drill Adams timed is just one piece of a model that will help engineers, so the intersection plan can adapt as traffic grows.

"We were just out there to see how the intersection operates currently versus how it's expected to operate with the buses," Adams said.

The reason Adams was timing buses at 1:30 p.m. instead of 6 a.m. is that delays at the intersection are expected to be longer when buses leave for picking up students after school than when they are leaving to pick up students from their homes in the morning.

That's because morning buses are dispersed according to their routes all over the Valley, while afternoon buses go directly to high schools and middle schools and leave in a shorter time period.

Lounsbury and Associates is performing the analysis under contract from D.J. Development, the company that owns the bus barn building and parking lot.

D.J. Development is leasing the lot to First Student, and is passing the Lounsbury reports to DOT, which maintains the highway, and to the Mat-Su Borough public works department, which maintains Hyer Spur.

In a preliminary report to D.J. Development, Lounsbury engineer David Krehmeier wrestled some of the data into plain English.

"The analysis did not reveal any significant problems during the AM departing peak hour or the AM returning peak hour . . ." Krehmeier wrote. "The analysis did identify excessive delays during the PM departing peak hour."

Krehmeier's preliminary analysis, compiled before Adams' numbers from last week were added to the mix, goes on to provide estimates of delays around the intersection on school day afternoons with various traffic schemes in place.

At its worst, the report mentions a delay "in excess of nine minutes" for traffic leaving Hyer Spur and turning left on the Palmer-Wasilla Highway — that scenario assumes that no improvements to the intersection will be made.

It's also a scenario that scored an "F" on the LOS scale, according to Krehmeier's report, and it's already been ruled out because D.J. Development and the Mat-Su Borough are working together to add a right-turn lane for Hyer Spur's traffic.

It's what highway engineers call a "free right" turn, and the sort of lane engineers know drivers will create for themselves even if it's not paved and painted into the traffic pattern.

The "free right" of course makes things easier for people turning left as well, and in this case it cuts the nine-minute delay to around six minutes. Krehmeier's report goes on to cover three other scenarios.

One scenario added an exclusive left-turn lane off Hyer Spur, another split bus traffic between Hyer Spur and a driveway directly from the bus lot onto the highway.

Both of those scenarios made getting off Hyer Spur faster, but both left the Intersection with an "F" for the left turn onto the Highway, which drivers heading toward Palmer from Hyer Spur will want to take.

Krehmeier's memo ends with a "signalized analysis" — engineer's jargon for, "What if we get a traffic light?"

Krehmeier wrote that the stoplight would keep the LOS for the left turn onto the highway at a "C" — its current score — and that the signal would, of course, slow traffic along the highway.

Dorwin Smith, owner of D.J. Development, said all of this is part of a plan to limit the impact of First Student's arrival.

"There's definitely going to be an effect. We can't stop that," Smith said. "But we're trying to minimize any effect that we might have on the local traffic."

Still, Smith said he can't predict if or when a traffic-control light might be placed at the intersection.

The Palmer-Wasilla Highway is a state road and those decisions are left to DOT, which will likely add the data Lounsbury gathered for Smith and possibly add more data of its own.

"I can't answer for what DOT might do. I know eventually there's going to be (a stoplight). There'll be an interchange eventually. It's just the way the Valley's going," he said.