Mohegan Sun and Wynn Resorts laid out plans Friday to help alleviate Boston-area traffic created by their proposed casinos.
The casino giants are vying for the lucrative eastern region gambling license, which is expected to be awarded in late August or early September.
Mohegan Sun officials, at a meeting before state gambling regulators at the Hynes Convention Center, said the casino's planned $1.2 billion resort on the Revere side of the Suffolk Downs horse racing track would include an estimated $45 million in transit-related improvements.
Wynn Resorts officials said their proposed $1.6 billion casino on a former chemical plant site in Everett would include about $50 million in such investments.
Both casino operators put forward a range of traffic-mitigating plans, including improvements to some of the area's most congested traffic circles. The casinos said their independent traffic studies suggest any impact to Boston-area traffic would come after the evening rush hour commute.
The casinos also said they would be limiting employee parking onsite and encouraging mass transit use while also staggering work shifts so that employee are not on the road during rush hour drive times.
Mohegan Sun officials billed their proposal as one of the largest "transit-oriented" developments in state history.
They said the MBTA's Blue Line would be steps from the casino's entrance. Patrons would also have quick access to Boston's Logan International Airport and be able to hop on shuttles to Boston destinations, including Back Bay and the seaport and theater districts.
Wynn, meanwhile, said its proposal would also have close access to the MBTA, include a public harborwalk around the Mystic River and provide bus shuttles, water transportation options and access to Zipcar and Hubway bike share programs on site.
Both casinos said the improvements would require no taxpayer money.
James McHugh, acting chairman of the Massachusetts Gaming Commission, said the transit discussion was an important primer for the panel as it heads into next week's public hearings on the rival plans.
Mohegan Sun's proposal will be aired at a meeting Tuesday in Revere while Wynn's plan will be heard in Everett the following day.
McHugh said transit impacts are among the top concerns for local residents, if past hearings are an indicator.