Pavement Markings and Lane Use

Key points

1. White lines separate traffic moving the same direction; yellow lines separate opposite directions.

   Source: Handbook p. 15

   “White lines separate traffic moving in the same direction. Yellow lines separate traffic moving in opposite directions.”
   Iowa Driver's Manual, Handbook p. 15

2. With a solid yellow line beside a dashed one, only the dashed side may pass when safe.

   Source: Handbook p. 15

   “Passing is not allowed on the side with the solid yellow line. Vehicles on the side with the dashed line may pass when safe to do so.”
   Iowa Driver's Manual, Handbook p. 15

3. Stop before the stop line, or before the crosswalk if there is one.

   Source: Handbook p. 15

   “you must stop before your vehicle reaches the stop line, or a crosswalk if there is one.”
   Iowa Driver's Manual, Handbook p. 15

4. You may enter and stop in a shared left turn lane before turning, but never use it for passing.

   Source: Handbook p. 16

   “Vehicles may enter and stop in the lane before making a left turn, but the lane cannot be used for passing.”
   Iowa Driver's Manual, Handbook p. 16

5. Over a reversible lane, a green arrow means use it and a red X means you may not.

   Source: Handbook p. 15

   “A green arrow means you can use the lane beneath it; a red “X” means you may not.”
   Iowa Driver's Manual, Handbook p. 15

6. On roads with 3 or more lanes your way, stay in the right or center lane except to pass.

   Source: Handbook p. 16

   “On a road with three or more lanes stay in the right or center lane except to pass.”
   Iowa Driver's Manual, Handbook p. 16

7. Never pass on the shoulder, paved or not.

   Source: Handbook p. 16

   “Never pass on the shoulder, whether it is paved or not.”
   Iowa Driver's Manual, Handbook p. 16

8. Drive in a bicycle lane only when turning, and look carefully for bicyclists.

   Source: Handbook p. 17

   “Motorists may only drive in bicycle lanes when making turning movements and must look carefully beside and behind their vehicle for bicyclists and cross with care.”
   Iowa Driver's Manual, Handbook p. 17

Numbers to know

3 questions from the Iowa practice test

1. 1. On a two-way road, what does a dashed yellow line beside a solid yellow line permit?

   1. Passing from both sides at any time
   2. Passing from the dashed-line side when it is safe
   3. Passing only by vehicles making a left turn
   4. No passing from either side
   Show answer

   Passing from the dashed-line side when it is safe. The side with the dashed yellow line may use the opposing lane to pass, but only after the driver confirms that the maneuver is safe. The solid-line side may not pass across its marking. The choice “Passing from both sides at any time” incorrectly removes the safety condition, while the choice “No passing from either side” ignores the different meanings of the two lines. Before crossing the center line, check distance, sight distance, oncoming traffic, signs, and driveways. The simple visual cue is that the dashed side has permission to consider passing, not a guarantee that passing is wise.

2. 2. What do white lines on the roadway separate?

   1. Only vehicles traveling above the speed limit
   2. Traffic moving in opposite directions
   3. Traffic moving in the same direction
   4. Roads that are closed to all traffic
   Show answer

   Traffic moving in the same direction. Iowa uses white lines to separate traffic moving in the same direction, while yellow lines separate traffic moving in opposite directions. That color distinction helps a driver interpret the roadway before changing position. The opposite-direction option describes yellow markings, and the speed and closure choices are unrelated to pavement-line color. Do not infer passing permission from white alone: inspect whether the line is broken or solid and follow any nearby signs. Identify the direction of traffic first, then make lane decisions from the complete marking pattern.

3. 3. What is a shared left-turn lane designed for?

   1. Passing slower traffic in the center
   2. Left turns from either direction
   3. Driving straight through an intersection
   4. Parking while waiting for a turn
   Show answer

   Left turns from either direction. A shared left-turn lane serves vehicles turning left from either direction. Its alternating arrows and yellow boundaries communicate that purpose. It is not a center passing lane, a through lane, or a parking space. A driver may enter and stop there briefly before making a left turn, but should not use the lane to overtake traffic. Scan for opposing vehicles already using the same center space, signal clearly, and enter only when the turn can be completed without conflict.

Source: the Iowa Driver's Manual, Chapter 2: Pavement Markings and Lane Controls. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.