BOSTON (CBS) – The Carbon Free Boston panel, commissioned by Mayor Marty Walsh, is suggesting a $5 congestion fee on cars driving into the city.

The panel released a report on how Boston can be carbon free by the year 2050.

“Maximizing energy efficiency […] Reducing personal use of personal vehicles and then electrifying as much as we can,” said Michael Walsh, the Technical Lead on the project and a professor at the Institute for Sustainability at Boston University.

In addition to a congestion fee placed on trips made to populated zones of the city such as the Downtown, Back Bay, and Seaport areas, the report also suggests a $5 parking fee.

“I’m not in favor of charging people $5 to come into the city of Boston,” Mayor Walsh told reporters on Monday.

Walsh says he does support a proposed $1 per mile fee imposed on ridesharing trips where a person rides alone.

“Currently, about 1 out of 25 trips ending in Boston uses ride hailing,” the report states.

Early next month, Boston plans to develop roadmaps to reduce carbon pollution in buildings and in transportation sectors.