Regulatory sign rules — Iowa Permit Test

A red circle with a red slash over a symbol means you cannot do what the symbol shows, such as turn left, turn right, or make a U-turn.

The slash crosses out the action, so whatever is under it is not allowed here.

Some regulatory signs have a red circle with a red slash over a symbol.

Maximum speed limits are for ideal conditions; you must slow down when the road is slippery or fog makes it hard to see.

A speed that is safe on a dry, clear day can make you skid or crash in rain, snow, or fog.

Maximum speed limits are for ideal driving conditions.

If a road's minimum speed limit is too fast for you, use another route.

Driving far below the flow on a fast road makes others brake hard or pass, which leads to crashes.

If this minimum speed is too fast for you, then you should use another route.

At a stop sign, stop at the stop line if there is one; then, if needed, pull forward to the edge of the intersection and go when it is safe.

Stopping at the line keeps the crosswalk clear, and creeping up lets you see cross traffic before you go.

Stop at the stop line if one is present.

Lane control signs mark where you can go and where you can turn, often with arrows, and stand beside or hang over the road.

Getting in the right lane early keeps you from cutting across traffic at the last second.

These signs mark where you can go and where you can turn, and often use an arrow symbol.

The no passing zone sign is placed at the beginning of the no passing zone.

The sign comes at the start, so once you see it, do not begin to pass.

The no passing zone sign is located at the beginning of the no passing zone.

Even where passing is allowed, you may pass only if it is safe.

A broken line or a lack of signs does not mean the way is clear, so you still have to check.

Where passing is allowed, you may do so only if it is safe.

What does a red circle with a red slash over a symbol mean?

You cannot do what the symbol shows. The slash crosses out the action, so whatever is under it is not allowed here. Iowa Driver's License Manual, p.8: “Some regulatory signs have a red circle with a red slash over a symbol.”