The statistics show that each of us is driving less. So why do our roads feel more jammed up? Why does it take longer to get anywhere? And what can we do about it? Some politicians have begun blaming Traffic Calming and bicycle lanes for the backups; saying that Complete Streets and pedestrian bulb-outs are making roads less safe because less accessible for emergency vehicles. Is there any truth to this? More fundamentally, is car congestion a problem to be solved or a solution to a problem?
A 2013 report from US PIRG showed that the average number of miles driven by the average American has been falling for about a decade, through economic booms and busts, and was down to mid-1990s levels. Millennials, our nation’s largest-ever generational cohort, are using transit and bikes more and taking fewer and shorter car trips, resulting in a 23% drop in the average number of miles driven. The percentage of high school seniors with a driver’s license fell 12%. Walkable city life is increasingly attractive to both young people and retiring baby boomers. The rise of on-line shopping, social media, and telecommuting has meant fewer quick car trips.
Despite these trends, as every driver knows, our roads are increasingly congested – not everywhere or all the time but for increasing periods at a growing number of key intersections and road segments. Congestion radically reduces the volume of traffic passing through a road section, the through-put, thereby creating a negative feedback loop that creates more backups. It’s estimated that USA drivers spend about 14.5 million hours every day stuck in traffic. Congestion not only costs us time – in 2011 Boston drivers collectively lost about 137 million hours, or about 53 hours per commuter per year – but also fuel and therefore pollution, health, and money. Not to mention frustration and occasionally murderous road rage. Although we Bostonians believe we’ve got it worst, car congestion seems to be clogging roads like kudzu in nearly every city in the country – and, by some reports, across the globe.
It’s true that a new report has said that the first four months of 2015 has set a new record in total vehicle miles in the US – up nearly 32 billion since the previous high in 2007, pushing gas consumption as well as prices upward. Lower gasoline prices and a recovering economy (consumer spending in May, 2015 had the highest month jump in six years) are two reasons for the jump, probably augmented by the continuing lack of viable alternatives to car driving for many people. But a four-month blip is not enough to explain years of delays.
We do know some things that are contributing to the larger problem – land use patterns and population growth are the most important. The low-rise dense designs that make older urban areas walkable and transit-efficient is illegal to build in many places today due to parking requirements, anti-mixed use and other zoning requirements, etc.
We know some things that may appear to be causative but actually aren’t – making roads safer for pedestrians and bicyclists, prioritizing bus and trolley traffic, even reducing the average speed of cars.
We know some things that (counterintuitively) do not help reduce congestion – most notably building more roads or adding lanes, all of which eventually fill up as our additional drivers decide to move into the new space.
And we know some things that do improve the situation, but usually only when they are applied as a group rather than singularly – improving road use efficiency using technology (signal timing, access controls, central monitoring) and other methods (car pools, HOV lanes, car sharing, perhaps driverless cars), increasing alternative options (transit both regional and downtown, bicycling), changing land-use patterns (Smart-Growth style transit-orientated development), requiring corporate and municipal Transportation Demand Management programs (incentives to not drive alone or to not drive at all), and (most effective of all) congestion pricing of various kinds.
What is needed is the cultural and political willingness to accept this knowledge and act upon it – while also coming to grips with the reality that the continuing imbalance of potential drivers to current or any plausible future amounts of road space means that congestion is a permanent part of a car-based reality.
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