On Point: Traffic tough to measure
On Point: Traffic tough to measure
How much longer will your commute be if 1,425 homes are built at Alameda Point? That’s the question residents who worry about the traffic development at the Point and elsewhere on the Island will create are asking.
Development both on and off the Island will create a lot of traffic on Alameda’s major roads and in the Webster and Posey tubes, the city’s planners and studies done for local development proposals say – impacts that some fear will overwhelm the Island’s arterials, creating commute hour carmageddon. But quantifying those impacts – effectively, predicting the future – is a more elusive matter than the studies let on.
Almost every time a developer proposes a new housing project on the Island, the city conducts a study to figure out how many more cars will traverse Alameda’s roads, tubes and bridges each day using live traffic counts and a computer model that takes both local and regional job and housing development projections into account. Using the model, the city calculates traffic impacts to major intersections and crossings down to the number of seconds of delay drivers experience, typically at peak morning and evening commute hours.
But those traffic numbers can range widely from study to study – even when the same intersections are being studied. Both the local and the regional job and housing development pictures are constantly changing (the economy is another factor driving traffic). Even the capacity of the city’s roads and crossings can change, based on the presence and timing of traffic signals. And no one really knows what people’s commuting habits will be decades from now.
“We’re predicting traffic in 20 years, in seconds,” City Planner Andrew Thomas said.
Take the intersection of Atlantic Avenue and Constitution Way. The environmental impact study for the original Northern Waterfront development plan, released in January 2006, listed the existing delay during morning and evening peak hours at 39 seconds each. But the Alameda Landing environmental study, published five months later, listed the delays at the same intersections at 22 seconds.
Traffic planners seeking to gauge existing traffic levels typically count cars for an hour a day for each of three days, Thomas said. But they won’t always get the same – or even similar – results.
“It’s going to vary every day,” he said.
Even if an intersection that operates at an acceptable level over the course of an hour studied, that doesn’t mean drivers stuck in traffic there aren’t experiencing gridlock, Thomas said. Bay Farm Island residents exiting via Island Drive in the morning – during an hour where studies have shown the traffic is at what would be considered an acceptable level – could still experience gridlock for the 20 minutes after parents drop their kids off at school and leave for work, he said.
“The studies (look at) delay over one hour,” Thomas said. “The problem at the bridge is for 20 minutes.”
The city’s most recent environmental study for Alameda Point shows that drivers entering some major Island intersections during commute hours could face delays of two minutes or more – even if Alameda Point isn’t among the developments on and off the Island that are expected to be built by 2035. That’s exponentially more than the point-in-time traffic studies say local drivers are experiencing now.
The city’s top planners are hopeful that they’ll succeed in their efforts to blunt the anticipated traffic by making it easier for people to get around without cars and attracting new residents who are less likely to drive. They acknowledged the numbers may not offer a clear reflection of the traffic drivers do and will face, but said they offer a general picture of what lies ahead and that picture contains a more congested commute and tubes at their capacity.
“There’s going to be significant traffic impacts at certain key intersections. Pretty consistently, we know more or less which intersections these are,” Alameda Point Chief Operating Officer Jennifer Ott said. “They’re built on assumptions, but the overall conclusions are the same.”
Ott said traffic in Alameda will worsen whether homes are built at Alameda Point or not. But she and Thomas said that the Island is unique in that its leaders do more to leverage development to gain transit, bike and pedestrian infrastructure and services that benefit everyone.
In a little over a month, the City Council will decide whether to move forward with development at Alameda Point’s Site A, which is proposed to include 800 of the roughly 1,400 homes to be built at the Point, along with 600,000 square feet of commercial uses, 15 acres of new parks and a new ferry terminal. And while the traffic presents a legitimate policy issue, Ott and Thomas said, it’ll be up to council members to decide whether the additional homes, jobs, parks and transit the development promises – never mind the opportunity to revitalize the long-shuttered base – are worth an additional traffic headache.
“Are we getting things? Is it worth it to us?” Ott said. “It’s a policy tradeoff, which unfortunately is a difficult decision.”