• Traffic Evaporation: What Really Happens When Road Space is Reallocated from Cars? | TheCityFix

    A reverse effect to traffic generation is the phenomenon of “traffic evaporation”: traffic that disappears when road space is reallocated from private vehicles to more sustainable modes of transport like walking, cycling and public transportation. While traffic evaporation has been well-documented for more than 20 years, most decision- and opinion-makers are still under the impression that reducing car lanes will make traffic worse.

    In 2001, researchers Cairns, Atkins and Goodwin published a paper in Municipal Engineer reviewing 70 road space reallocation cases, including testimonials from 200 traffic engineers and planners in multiple countries. The researchers concluded that predictions of unbearable traffic as a result of reallocating space away from private vehicles were, in most cases, alarmist. People adjusted their behavior in ways that traffic models did not accurately predict. When lanes were reassigned from car traffic to higher-capacity modes – sidewalks, bike lanes and bus or rail lanes – traffic issues were less severe than expected, and traffic volumes were significantly reduced.