Area residents will have to wait a little longer on the new Park & Ride lot off Hamilton Mill Road in North Gwinnett County.

The 900-space lot, about 3 1/2 miles from Hall County, was expected to open today.

It now is scheduled to open Aug. 1 to allow for some final improvements that would "be easier to do if we don't have cars parked there," said William Mecke, spokesman for the Georgia Regional Transportation Authority.

When finished, Xpress bus route 411 will take travelers from the lot, which is next to Walmart Supercenter and near Interstate 85, to the Mall of Georgia and then Midtown Atlanta. Route 413 will take commuters to and from downtown Atlanta.

The improvements are part of a $110 million U.S. Department of Transportation Congestion Reduction Demonstration grant Georgia received in 2008.

The grant is paying for easing traffic on Interstate 85 in DeKalb and Gwinnett counties through transit improvements, innovative technology and variable toll pricing.

The initial phase of the project is the conversion of a 16-mile stretch of high-occupancy vehicle lanes to high-occupancy toll lanes from Chamblee Tucker Road in DeKalb to Old Peachtree Road in Gwinnett.

Under the new system, cars carrying three or more people will be able to travel in the HOT lane for free, as is the case now with the HOV lane. People driving solo or with one other passenger will be able to drive in the lane for a toll that's based on the level of I-85 congestion at the time.

"An exact date ... for the official opening (of the new lane) will be set within the next week and a half," State Road and Tollway Authority spokeswoman Malika Reed Wilkins said Friday.

All commuters, including those who plan to drive with two or more passengers, will have to sign up for the "Peach Pass," through the SRTA website.

The pass, a thin sticker that adheres to a vehicle's windshield, is connected to an account established with the authority and automatically deducts tolls when used on the I-85 Express Lanes or Ga. 400.

The SRTA opened up Peach Pass registration Tuesday.

The state also is expanding a Park & Ride lot off Interstate 985 in Buford.

Some 350 spaces are being added to the site, which had 350 initially. Gwinnett Transit buses currently take commuters from there to downtown Atlanta destinations, including the state Capitol, each morning starting at 5:40.

"It's doing real well. It fills up every day," Mecke said.