The proposed widening of Interstate 5 through the Rose Quarter has drawn fierce opposition. But the latest skeptics are surprising: the Portland Trail Blazers, who play basketball there.

The Blazers might be expected to support a wider highway near their arena. Traffic to and from games at Moda Center is heavy. But on April 1, the Blazers organization wrote a joint letter with the city of Portland, expressing frustration to the Oregon Department of Transportation. That letter has not been reported until now.

The key complaint? The new highway design would block the route from Moda Center's parking garages to the highway, trapping fans near the arena for nearly an hour after games.

"If the current plan for those surface streets isn't revised," the team writes, "this change will create enormous delays for our customers' post-event departure and will result in increased traffic and gridlock on the surrounding surface streets of the neighborhood on a regular basis."

Blazers president Chris McGowan warns in the letter that the current project design would relocate a southbound on-ramp to I-5 and remove traffic from North Williams Avenue.

McGowan, joined by City Hall's chief administrative officer, Tom Rinehart, points to a 2016 study that says garages take 25 minutes to empty following a basketball game. The study concluded the proposed changes in the project could potentially double that time, and McGowan calls that figure "beyond what's tolerable for eventgoers."

The Blazers aren't satisfied by the state's proposed solution: hiring people to work as flaggers after games. McGowan calls that idea "unsustainable and potentially unsafe."

The Blazers' objection is important. Team owner Paul Allen's death last year has placed the Blazers' future in limbo, and city officials are eager to ensure the team doesn't skip town. Dissatisfaction from the franchise about ODOT's plans is just the latest snafu for a $500 million highway project that was delayed after environmental advocates punctured several of its rationales this spring.

The letter ends with a cheery reassurance: The Blazers are "confident that our concerns can be addressed during the design phase." But there's also a chilling message: The team says it's been warning ODOT about the parking garage problem since 2012.