It’s always a nice surprise to pull up to a parking meter and find time left over from the previous driver. But in Denver, new sensors could keep it from happening.

In a pilot program, sensors embedded in the pavement in 500 of the city’s 6,500 meters-equipped spots detect when a car leaves and then they wipe any time remaining from the meter. It isn’t refunded back to the driver, though — the city literally keeps the change.

Despite appearances to the contrary, Christine Downs from Denver’s Department of Public Works says it isn’t a nefarious plot to boost the city coffers. She says the sensored parking spots also provide useful information: “They can let us know how long people are actually staying [and] if there’s a certain stretch of the street that’s a lot more popular say than the next block over.”

Watch a news story about the sensors below.

[CBS Denver]