Iowa · Handbook chapter 4 · 4 min read

Chapter 4: Pavement markings and lanes

Iowa's yellow and white lines, yield lines, stop lines and crosswalks, reversible and shared left-turn lanes, reserved lanes, lane use and turning, bike lanes, sharrows and bike boxes, crosswalk beacons and sight-impaired pedestrians.

Why this chapter matters

Lines on the road tell you where you may drive, pass, turn and stop, often without any sign at all. Knowing them helps you pass safely and stay out of lanes that are not yours.

Line colors

• White lines separate traffic moving in the same direction.
• Yellow lines separate traffic moving in opposite directions.
• Where a solid yellow line runs beside a dashed yellow line, you may not pass from the solid side. Drivers on the dashed side may pass when it is safe.
• A double solid yellow line means no passing for either direction.

Yield lines, stop lines and crosswalks

• Yield lines are a row of solid white triangles pointing at you. They show where to yield under a YIELD sign or a "Yield here to pedestrians" sign.
• When a sign or signal requires you to stop, stop before the stop line, or before the crosswalk if there is one.
• Give way to people in a crosswalk or stepping into one. Many crosswalks have no painted lines, so watch for pedestrians at every intersection.
• Arrow markings in a lane show the movements allowed or required from it.

Special lanes

• Reversible lanes carry traffic one way at some times and the other way at others, usually marked with double dashed yellow lines. Overhead lights tell you: a green arrow means use the lane; a red X means do not; a flashing yellow X means the lane is for turning only; a steady yellow X means the lane is changing, so leave it as soon as safely possible.
• A shared left-turn lane in the middle of the road serves left turns from both directions. It has a solid and a dashed yellow line on each side and alternating arrows. You may enter it and stop before turning left, but never use it to pass.
• Reserved lanes, often marked with a white diamond, are for special vehicles such as buses or high-occupancy vehicles. Do not drive in one unless your vehicle qualifies.

General lane use

• On a road with two or more lanes in your direction, the left lane is generally for passing. With three or more lanes going your way, keep to the right or center lane and use the left one only for passing.
• Never drive or pass on the shoulder, paved or not, unless an official or device tells you to.
• Without signs or markings, turn from the lane closest to the direction you are going, and into the lane closest to the one you came from. Do not cross lane lines during the turn; change lanes afterward if you need to.

Bicycles

• Bike lanes are marked with solid white lines and bicycle symbols; some are painted green or separated by double lines, curbs or posts. Look for cyclists before crossing green pavement, and do not stop on it.
• You may drive in a bike lane only to make a turn, after checking beside and behind you.
• Sharrows (shared lane markings) remind drivers that cyclists use the lane, but they do not reserve any part of it for bikes.
• Bike boxes are green boxes at signals that let cyclists wait in front of traffic to turn safely.

Crosswalk beacons

• Rectangular rapid flashing beacons are pushed by pedestrians and flash amber. Stop for anyone in the crosswalk.
• Pedestrian hybrid beacons are dark until activated. Then: flashing yellow (slow down), steady yellow (prepare to stop), two steady reds (stop), then flashing reds (stop, then go with caution once the crosswalk is clear).

Sight-impaired pedestrians

A person with a white cane (or white with a red tip) or a harnessed guide animal is probably visually impaired. Take extra care; you must stop if they are in front of you or close enough to be in danger.