The road course is almost perfectly flat and runs clockwise. Two track configurations are possible. The modern Grand Prix circuit includes a hard chicane at the end of the front straight, referred to as the "Shelton Chicane" in honor of Vanport racing legend Monte Shelton, and involves 12 turns at a length of 1.967 mi (3.166 km). Without the chicane, the track has nine turns and a lap length of 1.915 mi (3.082 km). Portland is classified as an FIAGrade Two circuit.[3]
The City of Portland is working to establish the track as carbon neutral.[4] In 2023, an investigation revealed the use of leaded gasoline at the track, which poses significant health risks for spectators and residents near the track.[5] This occurs primarily during drag races, as unleaded fuel (often alcohol based) is used in major weekends.
History
PIR is built on the former location of Vanport, Oregon, which was destroyed on Memorial Day, May 30, 1948, when a railroad berm broke and water from the Columbia River flooded the city. After the flood, all that remained were the paved streets and concrete foundations of destroyed buildings.
The first races took place on these old city streets in 1961 during the Portland Rose Festival. Since then, the Rose Cup has become an annual event. Racing at "West Delta Park",[6] as PIR was known back then, was quite dangerous. Racers leaving the track unexpectedly could collide with leftover concrete foundations or fall into ponds.
Under the threat of losing the Rose Cup races, since many of the sanctioning racing bodies would no longer sanction races due to the deteriorating roads and dangerous obstacles, the track was finally paved in the 1970s.[6]
Portland is best-remembered as being the site of two of the closest finishes on a road course in Indy car racing history. In 1986, Michael Andretti lost fuel pressure on the final turn of the final lap, which allowed his father Mario to catch up and beat him to the finish line by 0.070 seconds. At the time, it was the closest finish of any race in Indy car history.
In 1997, in a three-wide finish, Mark Blundell beat second place Gil de Ferran by 0.027 seconds, and beat third place Raul Boesel by 0.055 seconds. For a road course race, it was the all-time closest finish in CART series history, as well as the closest three-car finish in series history.
In 1999 and 2000, the NASCAR Craftsman Truck Series ran a race at Portland International Raceway. The race was added after the demise of the ½-mile Portland Speedway that hosted races early in the series. The 1999 running saw the first (and as of 2021, the only) time there were more than one African-Americans competing in the same NASCAR top-three division race, with Bill Lester and Bobby Norfleet on the grid.
At the end of 2007 and the beginning of 2008, PIR went through a track renovation. The track was repaved with new asphalt and some minor changes were made to the track layout. Turns 4-7 were widened. The fence on the inside of turn 6 was moved to provide a better sightline through the corner. Turn 7 was sharpened to slow down racers prior to entering the back straight. Formula One-style curbs were also installed on the track.[7] The track reopened on February 23, 2008, with a ribbon cutting ceremony.
Trans-Am Series (1972, 1975–1987, 1990–1995, 2001, 2004–2005, 2009)
Lap records
The unofficial outright all-time lap record set during a race weekend is 0:55.760 seconds, set by Wayne Taylor on the old circuit layout, in an Intrepid RM-1-Chevrolet, during qualifying for the 1991 G.I. Joe's/Camel Grand Prix Presented by Nissan. As of August 2024, the fastest official race lap records at Portland International Raceway are listed as:
Category
Time
Driver
Vehicle
Event
Grand Prix Circuit: 3.166 km (2008–present)[9][10]
40% of races at the Portland International Raceway use leaded gasoline.[49] The urban location of the track, near the Portsmouth, Kenton and Piedmont neighborhoods of Portland, OR, has raised concerns about the potential for the Raceway to contribute to lead poisoning of nearby residents and a movement to end the use of leaded fuels at the Raceway.[50]