Do New Highway Lanes Equal Less Traffic?

As with many busy roadways across the country, there are times when traveling on the New Jersey Turnpike becomes a nightmare. Traffic, traffic -- and then more traffic -- tends to put a damper on any plans awaiting drivers once they reach their destinations.

The problem stems from a merge of car-only lanes with car-truck lanes, which backs up a 20-mile stretch that 120,000 drivers in both directions use each day. Engineers consulting with the state's turnpike authority have determined that one area has experienced "failure traffic levels" during morning and evening rush hours, and the conditions are expected to worsen to failure levels across the entire 20-mile span by 2011.

"Anyone who has traveled the turnpike through the middle of New Jersey knows this treacherous merge," said acting Gov. Richard J. Codey in announcing plans to extend the separation of lanes throughout the congested area. "It is one of the worst traffic spots in the state."

Codey said the $1.3 billion expansion project -- announced in December and still in the engineering and design stages -- is crucial for the region's commuters. "If we don't act, over the next several years, traffic growth in New Jersey, combined with a planned project in Pennsylvania to add a full-access interchange between the Pennsylvania Turnpike and the New Jersey Turnpike, will cause virtual gridlock," he said in a statement.

Ultimately, however, the area may face the same difficulties, according to several transportation experts. When highways reach traffic capacity, the answer can seem obvious -- more lanes equals more space for cars to travel, solving the problem.

The reality is that congestion is alleviated, but only temporarily. Then more people hear how great the new road is, try it out and voila! -- again there's bumper-to-bumper traffic.

The Dreaded 'Triple Convergence'

Widening roadways might solve the problem if the new lanes were only used by existing drivers, said Anthony Downs, a senior fellow at the Brookings Institution who has written several books about traffic, including "Still Stuck in Traffic."

But the dreaded phenomenon Downs calls "triple convergence" comes into play: People who previously traveled other routes, at other times and by other modes, converge onto the new, widened expressway until it's just as crowded as it was before.

"If you widen and that happens, more people are traveling on it, but it does not eliminate congestion," he said.

So why bother adding lanes? "You have to analyze the circumstances," Downs said. "If the goal is to increase the capacity of a system so more people can move on it at rush hour, it may make sense to expand. If the goal is release, I don't think congestion can be eliminated. I think congestion is an inescapable part of living in a modern [era.]"

Indeed, the problem is here to stay, and it promises to get worse. According to the 2004 Urban Mobility Report, a study by the Texas Transportation Institute released in September, each year American cities are falling further behind in the battle against traffic congestion.

The study looked at 20-year trends in traffic congestion and focused on 85 urban areas with populations greater than 500,000. It found that congestion has grown in areas of every size, and it lasts for a longer period of time. The average annual delay for every person using motorized travel during peak periods in the areas studied climbed from 16 hours in 1982 to 46 hours in 2002.

Congestion affects more of the roads, trips and times of day, the study found, with the worst congestion levels increasing from 12 percent to 40 percent of peak period travel. Meanwhile, free-flowing travel is less than half the amount in 1982.

Tim Lomax, research engineer at the Texas Transportation Institute and an author of the study, said in a few places congestion was "only" 70 percent worse than it was in 1982.

"In the bizarro world of traffic congestion, that qualifies as progress -- or at least a good thing," Lomax said.

The problem is expensive, too. The total cost of traffic congestion for the 85 areas studied was $63 billion in 2002, an increase from $61 billion in 2001 and up from $14 billion in 1982. It includes 3.5 billion hours of delays and 5.7 billion gallons of fuel consumed due to congestion. The study noted that this does not include the effects of uncertain delivery times, missed meetings, business relocations and other consequences of people being tied up in traffic.

Expanding existing roadways and building more roads will help the situation, Lomax said, though he agrees that traffic will still be a problem. Long-term congestion will still exist, "but the growth of congestion is going to be much less than if you don't build roads."

Various Solutions Needed

As communities grow and continue to encompass larger areas, the experts suggest a variety of approaches are required to make traffic levels tolerable.

"I don't think we should stop building roads altogether because of congestion," Downs said. He noted that some cities, such as Houston, have instituted high-occupancy toll lanes built next to regular lanes. People pay to use the lanes and the number of drivers is restricted, so those who do use it can travel 60 mph. "It doesn't eliminate congestion on the existing road," he said. "It does give people a choice to go faster on a given day."

A greater capacity does allow more people to travel during rush hour and it reduces the period of maximum congestion, Downs said. "If a road is constantly at maximum capacity and sort of a bottleneck, you're expanding the capacity of the bottleneck."

Lomax said a multi-faceted approach is best. "What we suggest is a range of solutions that all need to be looked at and considered. There isn't a simple sort of panacea solution.

"You need to look at adding more capacity -- highways or transit -- especially in growing areas," he said. "You need to operate that capacity as best you can, get as much productivity out of whatever system you have … and manage the demand on the system. Convince more people to telecommute or rideshare or work different hours. Take a longer-term look at the arrangement of the jobs, shops and houses in an area, the land use component of transportation."

In some cases though, expanding existing roads may be the best choice. Even "Car-Free" John Pucher, a professor of planning and public policy at Rutgers University who has not owned a car for 35 years and walks or bikes everywhere, is for the idea in the case of the New Jersey Turnpike.

"If it is not expanded, what happens is the traffic that it does not serve will simply be diverted to alternative routes and communities that cannot handle it," Pucher said. "Given the incredible amount of traffic passing through New Jersey, which is always going to pass through, I would much rather have it go through on the turnpike. This is coming from, in general, an opponent of any sort of roadway expansion."

Lomax also said people might be willing to pay tolls for high-speed options on the roads rather than being late to pick up their children from day care or missing their school activities due to delays.

"Right now if you're traveling, you have the option of going and sitting in traffic congestion or not going at all -- or going at a different time," he said.

Lomax also suggested that areas make it easier to get around by ways other than cars. "To me, it seems to be about providing options for transportation in terms of transit or biking or walking … it's not just wing-nut, granola-eating Californians that are talking about this."