Since 1985, when it was codified into Massachusetts law, Memorial Drive closes to cars "from the last Sunday in April through the second Sunday in November" from 11am to 7pm. During this time, the closed portions of Memorial Drive is known as Riverbend Park, and is open for people to walk, bike, roll, and otherwise enjoy the outdoors and the Charles River.
In 2020 and 2021, Riverbend Park, which currently extends from Western Avenue to Gerry's Landing, was expanded to include both Saturdays and Sundays, from 11am to 7pm on each day. This was part of an effort to create more outdoor space and allow for social distancing, in order to reduce the spread of COVID-19.
In 2022, Riverbend Park hours were further extended, beginning at 8am on Saturdays and continuing through 7pm on Sundays.