When the arrows painted on the roadway don't match the arrows on the traffic lights, something bad could happen - quickly.
And when the problem affects a busy street like Ulmerton Road, that makes the situation even worse.
This was the problem recently along the busy roadway near the Carillon business park in St. Petersburg.
Changes are made all the time in construction zones.
- Bay News 9's Real Time Traffic Reporter Chuck Henson takes an in-depth look at transportation issues around the Bay area.
Roadways and signs are constantly being marked and changed during the process.
Still, when Sherrie Lee was driving recently out of the Carillon business park recently onto Ulmerton Road, she knew something was not right.
"Well, I came up to the intersection and the light turned and there's three lanes that turn left," Lee said. "And the guy in the far left lane went straight. And the other two went to turn left. Luckily nobody got hit, but it kind of startled me because I've never seen that before."
Then she looked up at the traffic light.
"That light (to the right) actually says to go straight and obviously you would need to make the left."
Kris Carson with the Florida Department of Transportation cleared up the mess, explaining that the lens over the green turn left light was installed incorrectly.
"The lens was adjusted in place," Carson said. "Crews went up in a bucket truck to the signal head and adjusted the lens to point correctly (to the left instead of up/straight)."
The traffic signal miscue was not the only problem at the intersection.
The 'ONLY' street marking in conjunction with the left turning lane road arrows featured a backwards N.
Carson said crews would repaint ONLY correctly on the turning lanes.
There were no crashes reported at the installation in light of the installation errors.