DALLAS (AP) – Activists frustrated by the state of the roads in cities such as Dallas, New York, San Francisco and Boston are taking a do-it-yourself approach to improving them.

Groups of anonymous Twitter users have been establishing makeshift bike lanes and filling potholes in their communities, unbeknownst to their city governments.

Though the measures are meant to be temporary, the activists say they can show the public what could be and spur cities to make permanent improvements.

City officials consider such projects to be vandalism and say they can endanger the public.