Will expanding I-5 relieve congestion? Freight industry says yes


Despite numerous studies demonstrating that freeway expansions worsen congestion, the freight industry supports a proposed expansion of I-5 at the Rose Quarter. Members of the rail and trucking industries say the project will relieve congestion and improve safety.

“It benefits everyone, not just freight,” said Pia Welch, a FedEx project engineering specialist and chair of the Portland Freight Committee, a group that advises the Portland Bureau of Transportation. “I think it should help alleviate a choke point.”

While that’s probably the case in the short term, critics of the project argue better traffic flow will eventually worsen congestion by attracting more drivers. The authors of a famous 2009 study of road construction in major U.S. cities concluded that increased road capacity attracts more cars, creating congestion.  

But as Welch, Isselmann — and ODOT — point out, the project doesn’t actually add new lanes to the highway. Instead, the  I-5 plan will add auxiliary lanes that connect highway on and off ramps. Auxiliary lanes, the thinking goes, relieve congestion by separating drivers entering and exiting the road.

I 5RQ AuxLaneSchematic Draft2
ODOT's plan for improving I-5

David Hurwitz, an Oregon State University professor and traffic engineering expert, said auxiliary lanes will improve safety and reduce congestion, but possibly only for the short-term. According to induced demand theory, it is precisely the reduction in congestion that could attract drivers, leading to more traffic in the future.



Liming Wang, a transportation planning professor at Portland State University, said a perceived improvement in traffic is sometimes enough to attract more drivers, “For it to have a noticeable induced demand effect, one necessary condition is people are aware it’s less congested."


“They are probably the most efficient people on the road and they have to be,” said Sorin Garber, a transportation planning consultant who sits on the Portland Freight Committee. “There’s no question freight benefits from this expansion.”


The freight industry isn’t worried.

“Induced demand is an academic theory,” said Jack Isselmann, spokesperson for Greenbrier companies. “I think this project definitely will alleviate congestion.”

Even if the $450 million expansion does nothing in the long term for peak hour commuters, truckers will benefit.  

Truckers make the vast majority of their trips during off-peak hours. They can’t maneuver through narrow city streets, so they have no alternative but to take the freeway.

“They are probably the most efficient people on the road and they have to be,” said Sorin Garber, a transportation planning consultant who sits on the Portland Freight Committee. “There’s no question freight benefits from this expansion.”

Portland hosts the two biggest railroads in the U.S., Garber noted, but trucks still move 80 to 95% of products.

As retail continues to move online, Welch said, rail struggles to move goods quickly enough to satisfy online consumers.

“Rail is pretty full up,” Welch said. “It’s for goods that can take their time. People who buy online can’t wait.”  

Isselman said rail is the most efficient and environmentally-friendly way to move freight. But Greenbrier does rely on road infrastructure, like the I-5 expansion, and last mile connections with the trucking industry, he said.

“We all agree on the need for highway improvements,” he said. 

2 comments

  • jim
    jim Friday, 10 November 2017 16:29 Comment Link

    " The authors of a famous 2009 study of road construction in major U.S. cities concluded that increased road capacity attracts more cars, creating congestion. "
    That is NOT the reality:
    New roads fill because of several factors:
    People are attracted off of other, still congested, roads.
    People are attracted off of neighborhood streets, reducing neighborhood traffic.
    People travel at more convenient times (Isn't serving people the purpose of roads?)
    As population increases, road usage increases. (That's why we must increase road capacity in proportion to population increase.)
    People take trips that they wouldn't take in grid lock. Again, serving people is the purpose of roads.

  • Mike woodley
    Mike woodley Thursday, 09 November 2017 20:33 Comment Link

    By the time the state starts and finishes this project it will most likely be of little benefit and the funds will be inadequate because of the delays.
    The state never recognizes the urgency to get improvements underway.

Leave a comment

Make sure you enter all the required information, indicated by an asterisk (*). HTML code is not allowed.