What does the maximum speed sign mean?

This sign stands beside a road you are driving on in heavy rain, with spray from other vehicles cutting your view. What does the number on it represent?

The highest speed allowed in good conditions, which these are not

A posted limit is a ceiling set for a clear, dry road with normal traffic. Rain, snow, fog and heavy traffic all put the safe speed below it, and driving at the number in poor conditions can still be driving too fast.

This sign is posted on the road you are driving and heavy rain has badly cut how far you can see. What speed does it allow?

No more than the number shown, and less than that when conditions call for it

A posted maximum is the highest speed allowed in good conditions, not a speed you are entitled to hold in any weather. In rain, fog, snow or heavy traffic the safe speed is lower, and driving too fast for the conditions is an offence even when you are under the posted number.

You pass this sign as you come into a built up stretch of road. From what point does the number on it apply?

From the sign itself, and it holds until another speed sign changes it

A speed sign takes effect where it stands, so you should already be at or below the number as you reach it rather than braking once you have passed it. It then applies to the whole of that road until the next speed sign, quiet stretches included. Slowing afterwards means you were over the limit on the part of the road the sign was there to protect.

The sign ahead carries the word MAXIMUM above a number. It is raining hard and the traffic around you is moving well below that number. What does the sign mean for you?

The number is the highest speed allowed in good conditions, so heavy rain means slower than that

MAXIMUM is exactly what the word says, a ceiling, and it is set for a road that is dry and clear with normal traffic. Rain lengthens the distance you need to stop and shortens what you can see, so the safe speed drops below the posted one. Driving at the limit in bad conditions can still be careless driving.

A Manitoba road displays this sign with a number lower than the general area limit. What governs your speed?

The number shown on the sign

A posted maximum replaces the general default on that road. Even the posted maximum may be too fast when conditions are poor.

You pass this sign at the entrance to a Saskatchewan town. A few blocks later you turn onto a residential street with no speed sign of its own. What limit applies there?

The limit on the entrance sign, until another sign says otherwise

A speed sign at the entrance to a town or city sets the limit for the whole community unless another limit is posted. The 80 km/h default is only for roads with no posted limit at all.