In an effort to lessen the financial burden on people whose cars have been impounded for unpaid traffic tickets, the Pasadena City Council on Monday approved a contract for self-releasing immobilizing devices, or boots.

The device locks onto a car’s tire and makes it impossible to drive it until fines and fees are paid. But instead of being towed away, the device can be opened by car owners who receive a code from a toll-free number after all fines and a fee of $160 are paid via the Internet.

“It may not seem like it, but it is more of a customer-service option,” said City Manager Steve Mermell. “Drivers won’t have to go to tow yards and pay an exorbitant amount of cash to get their cars back. It’s inconvenient, but less inconvenient.”

Paylock, which makes the devices, currently has contracts with New York City and 25 other municipalities.

The company on Monday entered into a $126,000 a year contract with the city. The contract contains options for two one-year extensions. The city is expected to make about $64,000 in annual revenues. Currently, the city impounds about 400 cars each year.

Under the previous policy, cars would be impounded after five parking tickets went unpaid. Drivers would be forced to pay $132 in towing fees and another $121 for the car’s release. After that, a vehicle owner would be charged $32 a day for storage.

Under the new system, drivers will be given 72 hours to pay fines before the car is towed. If the fees are paid immediately, the driver does not have to leave his or her car.

Assistance will be provided for motorists who choose not to release the vehicle themselves.

“We’re trying to make it less of a financial hardship on drivers,” said Jon Hamblen, head of the city’s parking division. “This is a better option. We can collect on the unpaid citation and make it less expensive on the user.”