The new 900-space Park & Ride lot off Hamilton Mill Road in north Gwinnett County, about 3 1/2 miles from Hall County, is set to open Monday.
Georgia Regional Transportation Authority's Xpress coach service will start picking up commuters at the lot, which is next to Walmart Supercenter and near Interstate 85.
Route 411 will take travelers to the Mall of Georgia near Buford 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 I-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, unlike the HOV lane which only requires two or more people. 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.
Also, the state is expanding a Park & Ride lot off Ga. 20 and Interstate 985 in Buford, several miles south of Hall County.
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.
The project "is done except for punch list items.
All spots are open for use now," said Teri N. Pope, spokeswoman for the Georgia Department of Transportation's Gainesville office.