HOUSTON (AP) - It's something most 3-year-olds even know: Red means stop. Except when you run the light.

In recent years, Houston's installed cameras that take pictures of drivers illegally crossing intersections. It's a public safety venture that also increases revenue for cash-strapped municipalities.

Yet the trap has created controversy evolving into a debate over big government, due process and privacy.

Four years after Houston drivers faced the first flash, the question of whether the city's 70 cameras should remain is being posed to voters on the Nov. 2 ballot.

Critics say the devices are little more than a moneymaking scheme that don't necessarily save lives.

But studies show a drop in collisions at intersections with cameras because people drive more carefully.