The popular race venue, just outside Oregon's biggest city, held 24 Indy car races between 1984 and 2007, with Michael Andretti and Al Unser Jr. proving the most successful drivers (three wins each).

In the course of its 24-year history, the track length varied from 1.915 to 1.969 miles, and by the time of its final event, won by Sebastien Bourdais’ Newman/Haas/Lanigan Racing Panoz, the natural road course was measured at 1.964 miles.

Cotman, who designs street tracks but also advises on changes to be made to existing courses, told Motorsport.com: “The track since we last raced there is wider – it’s really nice and the surface is beautiful. The layout has been tweaked slightly but it’s all good.

“I haven’t been there for six months, but from when I went, I’d say there’s some upgrading that needs to be done because everything there is kinda temporary.

“There’s some changes to make to some of the debris fencing, for example, but that can be done easily enough.

“The problem is that although it’s a permanent facility, the costs involved are higher, because of the extra stuff you have to bring in compared with a track that has all of its structures permanent.

“So my worry would be that it doesn’t just need a promoter; more like a ‘promoter-plus’ – someone who’s willing to take more of a financial risk. Portland might need 80,000 people over a weekend to make it work for the guys paying the bills whereas Barber might be able to get away with 20,000.”

Another northwest venue touted recently has been a street race in Calgary, Alberta, Canada, some 13 hours drive away from Portland. However, Motorsport.com was informed in June that the outlook for this event is still in the balance, due to local resistance.

Mark Miles, CEO of Hulman & Co., IndyCar’s parent company, told Motorsport.com last month that expanding the schedule won’t be done just for the sake of covering more regions of the continent.

He said: “We’re not looking to add races just to add races. We want a calendar that puts us in good markets and produces really robust events. And we’re also aware that every additional race costs the teams money – we’re never going to forget that.”