TORONTO - Anyone heading to or from Pearson International Airport or into downtown Toronto during this month's G20 summit can expect major traffic delays.

Officials have released details of road closures -- mainly for motorcades -- that are planned because of the summit of world leaders.

That includes days leading up to the meetings in downtown Toronto June 26-27.

In a nutshell, police advise that if you don't have to travel into downtown Toronto during the summit -- don't.

Starting June 24, parts of Highway 401, the QEW, Gardiner Expressway, Highway 427 and Don Valley Parkway will be closed or have access restricted at times.

Police say motorists should expect major delays and should try to avoid these routes.

They recommend using public transit.

For security reasons, officials are not releasing specific times that roads will be closed or have access restricted.

And police advise travellers to allow plenty of extra time to get to the airport, although they don't expect flight cancellations because of the summit.

"All information right now suggests that your regular passenger flights will not be disrupted," Peel police Const. Adam Minnion said at a news conference.

"But having said that, some of the forthcoming road closures, particularly to the Gardiner, QEW, the 427 and the 401, will create greater traffic congestion issues."

There will also be road restrictions because of the security zone around the Metro Toronto Convention Centre, where the G20 leaders are holding their meetings.