Suzanne Jacobs

With permission from a local road agency, researchers in Michigan hacked into nearly 100 wirelessly networked traffic lights, highlighting security issues that they say are likely to pervade networked traffic infrastructure around the country.

The team found three major weaknesses in the traffic light system: unencrypted wireless connections, the use of default usernames and passwords that could be found online, and a debugging port that is easy to attack.

The Michigan researchers found that anyone with a computer that can communicate at the same frequency as the intersection radios -- in this case, 5.8 gigahertz -- could access the entire unencrypted network. It takes just one point of access to get into the whole system. More than 40 states currently use such systems to keep traffic flowing as efficiently as possible.