Q: In a construction zone with a speed limit of say 35 mph, where the speed limit is normally 55 mph, once through the construction when does the speed limit change back to 55? Is it at the “end road work” sign, or not until you see the next 55 mph sign, which could be miles away?

A: Somebody just read the last part of this question and thought, “come on, miles away? You’re just being dramatic.” Not necessarily. The state Department of Transportation Traffic Manual specifies where speed limit signs should be located “for maximum awareness.” It includes the places you’d expect: when the speed limit changes, at major interchanges or intersections, and at state and city limits.

Oh yeah, there’s one more on the list. In rural areas, speed limit signs are spaced at 10-to-20-mile intervals (for maximum awareness.) No, that’s not a burn on WSDOT. There’s a science to proper sign placement, and they know what they’re doing.

If you slow down for a construction zone on a rural highway and wait for a speed limit sign to resume your previous speed, you might spend your next 20 minutes with a long string of annoyed drivers behind you. No one wants that. But I want to highlight the positive unstated part of your question. You’ve implied that you slowed down in the construction zone. Highway construction is a dangerous job, and the safety of those workers hangs on the driving behaviors of strangers in multi-ton projectiles.

Thank you for respecting the speed limit and those workers. To avoid confusion, I should point out that the law establishes two kinds of work zones. The one you’re referencing is called a “roadway construction zone.” Those are the more established construction sites that generally have lots of advance notice with signs and pylons to direct traffic.

In those zones, drivers follow the speed limit sign posted for the zone. According to WSDOT, a roadway construction zone begins at the first warning sign and ends at either the “end road work” sign or the last temporary traffic control device. If you come to what looks like the end of a work zone but don’t see an “end road work” sign, it’s OK. As long as there are no more pylons, barricades or construction-related signs, you’re free to resume the regular speed limit.

The other type of work zone is called an “emergency or work zone.” That is the area, defined by law, as 200 feet before and after an emergency vehicle, tow truck or construction/maintenance/service vehicle with flashing lights either stationary or moving slowly on the road or shoulder.

Think traffic stops, collision response, broken down vehicles and emergency repairs. Given the often impromptu nature of those zones, there are no signs or advance warning. Drivers are required to move over a lane if possible, or slow down at least 10 mph below the posted speed limit.

For both kinds of work zones, violating the law has enhanced consequences. A speeding ticket is double the regular penalty and cannot be reduced. Anyone who drives “in a way that endangers or is likely to endanger any people or property or who removes, evades or intentionally strikes a traffic safety or control device, is guilty of reckless endangerment of roadway workers.”

That’s not just a traffic ticket–it’s a gross misdemeanor. Along with the fines (and theoretical potential jail time), it’s a 60-day driver’s license suspension. Plus, there’s that embarrassing moment when the driver’s potential future romantic partner asks, “So what did you do to get a criminal record?”

Doug Dahl writes a weekly column for this newspaper. He is with the state Traffic Safety Commission.