1859 Central Park opens to the public.
1899 Cars first allowed on park drives, by permit only.
1906 The "loud and odiferous" nature of autos in the Park is acknowledged by The New York Times.
1955, 1960 Park is without cars for a few days of national bicycle races, including the Olympic trials.
1966 Weekends car-free 6 am to 6 pm, Memorial Day to Labor Day.
1967 Weekend and Holiday hours expanded to year round in Central, Prospect and Forest Parks.
1968 Along with weekends and Holidays, loop drives are car-free on Tuesdays and Wednesdays 7 pm to 10:30 pm, Memorial Day to Labor Day.
1969 Car-free hours: Saturdays, sunrise to 7 pm. Weekdays unchanged.
1972 One-time experimental "Parks Week", May 22-26, Monday to Friday 11 am to 3 pm, the first weekday car-free hours.
1975 Weekday no-car hours instituted, Monday to Friday, 11 am to 3 pm, June 2 to Labor Day.
1978 Car-free schedule extended: Weekdays 10 am to 4 pm and 7 pm to 11 pm. Car-free "summer season" extended to May 1 to October 22. (The NYC Marathon)
1979 Blue Ribbon Panel's plan (PDF) accepted. Weekends are made car-free full-time. Weekday car-free hours reduced to 10 am to 3 pm and 7 pm to 10 am. Bike/pedestrian lane added to loop.
1981 Cars allowed to intrude on lower loop, 6th Ave to 72nd St. during weekday car-free period.
1992 W. 110th St., W. 106th St and 5th Ave. entrances closed to cars.
1994 "Summer hours" extended to 10 months of the year; January 1 to first week of November (marathon).
2004 Speed limit on the loop drive reduced from 30 mph to 25 mph. West 90th and East 102nd Street entrances and exits closed to cars. West 77th and East 90th entrances closed to cars. West 72nd street slip-ramp closed to cars. People reclaim overnight and early mornings in the park. Cars get to enter 7 am to 10 am and 3 pm to 7 pm. HOV 2+ rule on West drive during morning rush hours.
2006 Fractional closures of the loop drive instituted. East drive closed mornings and West drive closed afternoons.
2007 Morning car-free time on West drive extended one hour, from 7 am to 8 am.