Rules of the Road

Do you really need to slow down for that speed limit transition?

City/county boundaries can mix with a variation from the standard speed limit rule in the Revised Code of Washington to create some confusion for drivers.
City/county boundaries can mix with a variation from the standard speed limit rule in the Revised Code of Washington to create some confusion for drivers. Doug Dahl

Question: After turning onto Portal Way to go north from Grandview Road, the speed limit is 50 mph. Then in about a quarter mile it drops to 35 mph, and then in about 50 feet it changes back to 50 mph.

At first I thought it was because of the cars driving in and out from the storage units. But after I went back and double checked, I saw it goes back to 50 mph before the driveway into the storage units.

What’s the point of having the speed drop down to 35 mph? Are we supposed to slam on our brakes to slow down to 35mph, only to have to accelerate again back to 50 mph?

Answer: I can explain. Most of the time these transitions aren’t so weird, but you found an odd one. This situation is a result of city/county boundaries mixed with a variation from the standard speed limit rule in the Revised Code of Washington.

If you’ve ever received a speeding ticket, you might have noticed that the authority to issue that infraction was noted as RCW 46.61.400. That’s the section of the Revised Code of Washington that, in addition to declaring speeding to be a violation of the law, sets the maximum speed limits for various types of roads in Washington. Here’s how it breaks down:

▪ City and town streets: 25 mph.

▪ County roads: 50 mph.

▪ State highways: 60 mph.

Already you can probably think of roads that fit those descriptions that don’t have those speed limits. The next few sections of the law provide ways for state and local jurisdictions to increase or decrease speed limits, within some boundaries. Whatcom County, in its county code, set the speed limit for county roads as 35 mph unless otherwise posted.

When a road transitions from city limits into the county, you’ll find a sign that states “Whatcom County speed limit 35 unless otherwise posted.” That’s actually what’s going on in the situation described in the original question. It’s just that the boundary lines make this particular location a little strange.

If you were to take a look at map showing the city limits of Ferndale, you might be surprised, as I was, to see how far north a narrow arm of the city reaches. As you can guess, based on where the answer to this question is going, on Portal Way the city limit is just north of Grandview Road, right about where that “35 unless otherwise posted” sign is located.

Here’s what’s happening: The Manual on Uniform Traffic Control Devices specifies that speed limit signs should be installed beyond major intersections to let drivers coming from another road know the speed limit. That’s why the first 50 mph sign is there. A quarter mile later, the road transitions from inside Ferndale city limits to Whatcom County.

That’s why the “35 unless otherwise posted” sign is there. Two hundred feet later, there’s another 50 mph sign, because Portal Way is “otherwise posted.”

Bottom line: since there is a posted speed limit of 50 mph, you don’t need to slow down to 35 mph for the 200 feet between the signs. Consider the 35 mph sign a reminder that if you don’t see a speed limit sign on a county road, you should default to a speed of 35 mph.

Road Rules is a regular column on road laws, safe driving habits and general police practices. Doug Dahl is the Target Zero Manager for the Whatcom County Traffic Safety Task Force. Target Zero is Washington’s vision to reduce traffic fatalities and serious injuries to zero by 2030. For more traffic safety information visit TheWiseDrive.com. Ask a question.

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