The term "pedlock" followed "gridlock" in the 1980s, but really didn't catch on until the 2000s.
19 May 1986, Newsday (Long Island, NY), "Cars, Pedestrians 'Fair' Well in City; No Tieups As Crowds Hit Street," by Larry Bivins, Kevin Flynn and Ellis Hennican, City, pg. 3:
Ninth Avenue is elbow-to-elbow people, rather than the usual bumper-to-bumper cars, at the international food festival.
"Standstill Sunday" never arrived yesterday and that was good news for motorists and walkers in Manhattan and for city officials looking ahead to July 4th.
With up to 1 million people expected to flock to street fairs, shows at the Jacob K. Javits Convention Center in Manhattan and a Fifth Avenue parade, officials last week warned of gridlock for cars and even pedlock for pedestrians.
30 December 2003, The Independent (London), pg. 6:
Condition of being so crowded that pedestrians are unable to move easily in any direction (e.g. "I wish they'd introduce a pedestrian-management system on Oxford Street's pavements. It's pedlock over Christmas.")
29 August 2004, New York (NY) Times, pg. 7:
But as any urban dweller will testify, the hazards presented by nattering mobile users do not begin and end behind the wheel.
It may sound insignificant, but pedestrians talking on cellphones have become a major cause of ''pedlock'' and subsequent ''ped-rage.''
20 April 2005, New York (NY) Daily News, pg. 39:
In fact, walkers have to win or 42nd St. is headed for what Transportation Alternatives chief Paul White calls "ped-lock." Simply put: As the sidewalks become impassable, pedestrians spill into the street, making the streets impassable, etc., etc.