I'll be working in Bellevue for 2 weeks this month, and one week in mid-July. I doubt I'll fit a bicycle or helmet on the plane, but I'm still curious about bicycling locally for transportation. Depending on auto congestion and bus service, a cheap bike on CL might be interesting.

(a) Bike Lanes - mandatory? Useful??
Is bike lane use required by law or enforced by motorists? Are bike lanes built well enough that bicyclists use them voluntarily?

(b) Helmet laws
How(If) is helmet use enforced? Depends on officer's mood? Used to hold bicyclists responsible for all injuries if they are not helmeted?

My experience with bike lanes from MD - NY is mixed (a few well designed, some completely unusable), but I haven't been to Seattle yet.

Are you going to ride in Seattle, Bellevue, or both? Where do you plan to stay?

The answers to everything you just asked vary a lot depending where you are. I've heard helmet laws are enforced in the financial district in downtown Seattle. I haven't seen or heard of people having an issue otherwise. Some of the bike lanes and MUPs are very useful. I wouldn't take the lane on Aurora unless I was feeling suicidal but most streets aren't a problem. I can't say much about where to ride or avoid east of the lake.

I'll definitely be staying in Bellevue, near the office about ½ mile east of Bellevue Square, so it would be nice to ride in Bellevue a few times.

It sounds like Seattle might have some interesting/scenic rides for next weekend; I'm not sure if I'll have a bike or how easy it is to get it to Seattle.

I almost never go into Bellevue so I can't say much on that but I'd suggest at least riding into Seattle city limits on the I-90 trail. You'll be on the edge of a floating bridge, right above the water; if it's a clear day you'll have a view of Mt Baker to the north, it's a really nice ride. You can do a loop in town or turn back at the end of the bridge.

Look at Strava's heat map for an idea of where people ride most out here, it's usually for good reason.

https://labs.strava.com/heatmap/#12/-...0084/blue/bike

Thanks for the suggestion (and the Strava link).

One of the best nearby rides is the Mercer Island velodrome.

Mercer Island Opens World?s Largest Velodrome ? The Mercer Island Distorter

I worked in Bellevue for years and rode to work downtown every day. Even though I don't work downtown anymore I still ride through the city on a regular basis. There are roads in Bellevue that are fine to ride on and some I would never ride on. Motorists are used to seeing cyclists on the road and generally share nicely although you may run into the occasional jerk. I've seen cops enforcing helmet laws. You'll generally stand out if you don't wear one.

The Strava Global heatmap is a great resource to see what roads cyclists use. The City of Bellevue also has a bike map that you can download of their website.

Another good loop from downtown Bellevue is the Lake Washington Loop. Just search it online and you'll find maps, etc. plus the loop is signed.

Helmets are required - King County bike rules: Bicycle safety & laws - Rules for the road - King County

If you're in Bellevue, you can get on the Burke-Gilman trail at Marymoor Park and take it all the way into Seattle.

- King County

To be clear, it's the Sammamish River Trail that starts at Marymoor Park. The Sammamish River Trail becomes the Burke Gillman trail in Bothell. Would not want someone to be riding around Marymoor Park looking for Burke Gillman trail signs

Thanks for the mentions of the Lake Washington Loop, especially confirming that the I-90 trail is bikeable all the way from Bellevue across Mercer Island into Seattle. The weather is supposed to be nicer tomorrow, so I'll try this then.