CHICAGO (CBS) — Burned twice in the past three years by impostors who stole buses, the CTA is going high-tech in its attempt to prevent it from happening again.

One thief, in September 2010, donned a stolen uniform and picked up passengers until he hit another bus. The second, 17 months ago, used a stolen CTA radio, took a bus, and drove 12 miles non-stop from one bus garage to another.

Before the 2010 theft and accident, CTA buses didn’t even have keys. Soon, said CTA President Forrest Claypool, its buses won’t go anywhere unless they are driven by the assigned driver, who will have to punch in a changeable code.

“It is a PIN-code system that doesn’t allow the bus to be operated by anyone other than the driver assigned to that bus that day for a 24-hour period,” he said.

The CTA developed the system in-house. It will spend $762,000 to install the system on its fleet of more than 2,000 buses and spare them the embarrassment and potential lawsuits caused by such thefts.