At low speeds, an accelerometer determines the position of the lights by reading the pull of gravity.

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Later in Brooklyn, a squad car hit its siren and lights as he tried to pull a U-turn on Flatbush Avenue to get back to the Brooklyn Bridge.

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We all see it on the roads, drivers who speed past only for you to pull up behind them at the next set of lights.

BBC: Traffic

And that's why the endeavor required a pair of 600-horsepower push-and-pull trucks, along with dozens of workers leading and following to displace and restore countless traffic lights, utility poles and the occasional pesky palm tree to make way for the shiny red caravan.

WSJ: Levitated Mass | Arrival of a Rock Start | By Arnie Cooper

To the left of the numbers are indicator lights letting you know whether it's locked or unlocked -- once unlocked, you can pull the metal "u" bar out from just underneath.

ENGADGET: Social Bicycles announces availability by end of summer, we go hands-on (video)