Three computer scientists studying Uber’s surge pricing have devised a simple recommendation for thwarting the algorithm: Walk.

The car-service app increases prices when demand for the service is higher than normal, ostensibly to attract more drivers to the area. In their study, the researchers at Northeastern University wrote a computer script that, in effect, created 43 virtual Uber users, each repeatedly requesting rides from various locations in New York City and San Francisco. Based on the prices and locations of cars that Uber offered these virtual passengers, the researchers learned a few interesting things about how surge pricing works.