The problem the proposed transportation sales tax, or T-SPLOST, purports to solve would seem obvious. Here’s how the first advertisement by a group pushing the tax framed the issue:
“Metro Atlanta, we have a problem: one of the longest average commutes in America, over an hour a day. Five hours a week you don’t spend with your family; 260 hours a year.”
But what if the length of our commutes isn’t a problem we can solve? At least, that is, not by building new infrastructure to relieve congestion.
That’s the implication of new data from INRIX, a private company that tracks traffic information.
The latest INRIX Traffic Scorecard, updated this week with data through April, shows traffic congestion increases the average commute in metro Atlanta by only about 10 percent — less than six minutes a day.
Let me repeat that: Congestion adds less than six minutes to the average metro Atlanta commute. And to reduce — not eliminate — that six-minute problem, we are asked to tax ourselves an extra $7.2 billion in 10 years.
If you’ve driven a car around here, right about now you may be thinking these figures are baloney. So let me briefly explain where they come from.
INRIX, based in Washington state, tracks traffic data in America’s 100 largest urban areas, including metro Atlanta (it defines each region the same way the Census Bureau does). It does this by collecting information about drive times from 100 million truck drivers, taxis, airport shuttles, delivery vehicles and motorists who use its smartphone app in 30 countries. It then sells the relevant data to federal and state transportation agencies, including the Georgia DOT, said Jim Bak, co-author of the scorecard.
INRIX compares drive times when traffic flows freely to those at rush hour, then calculates the amount of “wasted hours” congestion adds to the average commute.
In Atlanta, based on the latest data, commuters would drive 241.9 hours each year — almost 56 minutes each workday — even if traffic always flowed freely. Congestion adds 25.4 hours a year, or almost six minutes a day.
What’s more, our “wasted hours” are decreasing even as employment begins to recover. Fuel prices, Bak said, are offsetting the return of commuters to the roads.
So, while the INRIX data show metro Atlantans have the sixth-longest average commute in America, we rank only 14th in “wasted hours.” The clear takeaway is that the chief reason our commutes are so long is that so many of us live so far from our workplaces.
Your mileage may vary, of course, depending on where you live. Certainly, in some parts of our region the average commute tends to be longer.
But another interesting INRIX finding is that, while metro Atlanta is 14th in overall congestion, our worst corridor ranks only 114th nationwide. Twenty-six other cities have a stretch of road more congested than Ga. 400 south between Old Milton Parkway and Holcomb Bridge Road.
This reinforces the idea our congestion is evenly applied to numerous roads. And that may explain why there’s so much disagreement about where T-SPLOST funds ought to be spent.
Now for some optimism: We may be able to improve conditions even without building new lanes — by relying on data from INRIX or its competitors, such as NAVTEQ and TomTom, to better manage traffic flows.
Bak gave an example from Washington: A curvy stretch of I-5 from the airport north to downtown Seattle. Washington’s DOT installed electronic signs on which they can adjust the speed limit according to real-time traffic information.
“It slows the cars that are coming into congested areas, which delays the gridlock, which allows traffic to flow better,” he told me by telephone. “People would be flying at 65 miles per hour, and all of a sudden they come across the curve” to find stopped traffic, often causing wrecks — and more delays. The variable speed limit signs have reduced accidents there by 30 percent, Bak said.
One mile of a highway lane can handle only so many cars an hour. Gridlock occurs, often for a disproportionate length of time, if that threshold is surpassed. Slowing oncoming traffic as roads become congested may prevent the worst traffic.
So, maybe the questions we ought to ask ourselves are not how much to spend, and where, but whether we can afford to subsidize people’s choices to live far from work — and, if so, whether there’s a cheaper and smarter way to do that.
– By Kyle Wingfield