Beyond color and shape, each sign carries a specific message. Here is what the handbook's sign pages say each one requires. A red circle with a slash always means "don't."
Know the rule
A red circle with a diagonal slash means the movement shown is prohibited.
Handbook p. 45 ↗Regulatory messages:
- Do not exceed the posted speed
- Do not walk or bike on any part of the right-of-way
- Do not turn right on a red signal
- Trucks must use the right lane
- Do not drive a vehicle over the posted weight limit beyond this sign
- Travel only in the direction shown on the posted (one-way) street
Lane-use and parking messages:
- Use the center lane only for left turns
- Make a left turn when you're in the lane below or facing this sign
- Keep right of this sign
- Do not park to the right of this sign
- Do not stop, stand, or park as the sign directs
Warning messages about the road ahead:
- Merge left; road narrows ahead
- One-way operation on a bridge may require a stop ahead
- Keep to the right of a divided highway; two-way road: keep right of approaching traffic
- Slippery roadway after rain, frost, etc.: reduce speed
- Traffic signal ahead: prepare to stop
- Traffic merging from the right: be alert
- Steep downgrade: trucks slow and shift to a lower gear
- Restricted clearance: over-height vehicles take another route
Curves, ramps and animals:
- Slow to the posted speed on the ramp
- Take the curve to the right at the advisory speed
- Winding road ahead: adjust to the advisory speed
- Sharp turn to the right in front of this sign
- Deer or caribou crossing: be alert for animals crossing unexpectedly
20 mph
Speed the school crosswalk and school children signs direct you to slow to
Handbook p. 45 ↗Other signs on these pages:
- Bike route extends to the right; watch for bicyclists
- Rest area open to the right
- Road closed to all traffic; detour
- Space reserved for persons with disability plates or placard
- Roundabout ahead
Know the rule
Service signs (white on blue) mark conveniences such as gas, phone, food, lodging, rest areas, campgrounds and litter barrels.
Handbook p. 44 ↗Put it into practice
A sign shows a truck on a steep slope. That warns of a steep downgrade where trucks must slow and shift to a lower gear. Expect slow trucks and control your own speed on the way down.