99percentinvisible:

A “sneckdown” ( combination of “snow” and “neckdown” – another name for a curb expansion) uses snow formations on the street to reveal the space cars don’t use. Advocates can then use these sneckdown photos to make the case to local transportation officials that traffic calming interventions like curb bumpouts and traffic islands can be installed without any loss to car drivers. 

From What Snow Tells Us about Creating Better Public Spaces on E. Passyunk Avenue