Q: What are the rules on what bike lanes can be used for? I’ve scoured state and local codes and can find no mention of that. Surely, they are reserved at least to some degree for bikes.

A: Obviously, you can’t drive in a bike lane, right? That would defeat the whole point of having them. But where does the law say that? You’d think there would be a law in the traffic code that says, “Don’t drive in the bike lanes.” If there is, I couldn’t find it. But it must be somewhere, because the Washington Driver Guide says it’s not allowed: “Do not drive in a bicycle lane except when making a turn or when you need to cross the bicycle lane to park near the curb.”

Some cities in Washington have local laws prohibiting driving in bike lanes. Washington’s traffic code does have a law that prohibits riding a moped on a bike path, so it seems reasonable to infer that other motorized vehicles would also be prohibited. And the Rules of the Road at least acknowledge that there are “parts of roadways set aside for the exclusive use of bicycles.”

But oddly, if we search outside the traffic code we’ll find what we’re looking for. In RCW Title 35, which is mostly about municipal budgets and infrastructure, there’s a law, originally from 1899, that says, “It shall be unlawful for any person to lead, drive, ride, or propel any team, wagon, animal, or vehicle other than a bicycle, electric personal assistive mobility device, or similar vehicle upon and along any bicycle path.” (The electric part was added in 2002.)

The motivation for that law 125 years ago wasn’t protecting cyclists from cars (at least as we know them today). Cars were barely a consideration in 1899. That year, US car manufacturers produced a total of only 2,500 vehicles, and the cars had a top speed of somewhere around 12 mph.

Maybe you’re wondering if that law is still relevant. Based on more recent action by legislators, I’d say it is. Their addition of the electric personal assistive mobility device as an allowed vehicle signals that it still applies to modern bike lanes. I’ll add that most comparable traffic violations are civil infractions but this one is a crime.

Drivers don’t belong in bike lanes, but can anyone else use them? The law allows vehicles that are “similar” to bikes, such a hoverboards or onewheels. I don’t know how broad a net the word “similar” casts; I’m guessing it may include human-powered and electric vehicles of comparable size and speed. The law I mentioned earlier that prohibits mopeds does allow electric bikes and motorized foot scooters in bike lanes, with some limitations.

How about pedestrians? Maybe, again with limitations. Pedestrians are allowed to walk in the roadway when there are no sidewalks or shoulders, with a requirement that they’re “as near as is practicable to the outside edge of the roadway facing traffic,” which is where the bike lane is. Realistically though, do any roads without sidewalks and shoulders have a bike lane?

To sum it up, bike lanes are for bikes (and similar vehicles).

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