This truck is moving at a snail’s pace. Am I allowed to pass here?

Can I legally turn left into this strip mall driveway, or should I make a U-turn at the light ahead?

These are the kinds of questions that some drivers occasionally ask themselves. Unfortunately, this level of uncertainty and indecision can sometimes lead to a dangerous driving maneuver — or a traffic ticket.

But a solid grasp of what lane markings mean can help take away the confusion. Here’s a review of what some common lane markings mean, provided by the California Department of Motor Vehicles:

• Solid yellow lines mark the center of a road used for two-way traffic.

• Broken yellow lines indicate that you may pass if the broken line is next to your driving lane.

• Two solid yellow lines indicate no passing. Never drive to the left of these lines unless you are in a carpool lane/High Occupancy Vehicle (HOV) lane that has a designated entrance on the left, or you are instructed by construction or other signs to drive on the other side of the road because your side of the road is closed or blocked. You may, however, turn left across a single set of double yellow lines to enter or exit a driveway, to make a U-turn, or to travel into or out of a private road.

• Two sets of solid double yellow lines spaced 2 feet or more apart are considered a barrier. Do not drive on or over this barrier, make a left turn, or a U-turn across it, except at designated openings.

• Solid white lines mark traffic lanes going in the same direction, such as one-way streets. Solid white lines can also mark the right edge of the road, helping drivers to stay on the road at night or in bad weather (including fog).

• Broken white lines separate traffic lanes on roads with two or more lanes in the same direction.

• Double white lines are two solid white lines that indicate a lane barrier between a regular-use and a preferential-use lane, such as a carpool/HOV. Never change lanes while in these lanes; wait until a single broken white line appears. You may also see these parallel lines in or near freeway on and off ramps.