And to add to this: I can imagine an urban engineer walking through Amsterdam (or any other dutch city, really) to just despair. The sheer amount of infra Amsterdam has built to be this bike friendly is of an epic scale: The dutch have been doing their infra projects with 'bikes and walking comes first' in mind for about 50 years now; no wonder it seems undoable to reproduce that kind of thing in less than a decade.
For those who haven't been there: Entire, completely separated two-way wide bike paths with their own bridges and tunnels, nowhere near car roads. Huge swaths of the city that are _solely_ for bikes and walking, with only a few roads dedicated for cars. (i.e. to travel between 2 places in inner Amsterdam by car, generally you drive _away_ from your destination towards the ring, hop on a ring road, drive _past_ your target, and then drive back into the inner city. And yet this is faster than the US style because it avoids incessant waiting in queues and traffic lights, and there's far less traffic as bike/walk is a workable alternative). The bikes, where they even have to cross a car road, get preferential traffic lights and all the bike paths have double detector loops - your bike traffic light tends to switch to green just as you approach the intersection, and if you're the last in a peloton of bicycles you might notice the light switching to orange juuust as you pass the light. That's not a coincidence.
Yeah, you can build that up. But it takes quite a while, and requires a financial outlay that seems daunting unless you smear it out over 50 years.
However, perhaps, go to Copenhagen. It's often listed as just as bike friendly, if not _more_ bike friendly than cities in The Netherlands. This is hogwash (SOURCE: I've been in, and biked in, both places, recently). Copenhagen is great, Amsterdam is far better. However, Copenhagen looks much more doable.
Where Amsterdam has completely separated bike infra and no major car roads running through the center, Copenhagen has giant 3-lane-each car highways right through the busy city center, and almost no separated bike infra. What Copenhagen does have, is one entire lane of car traffic dedicated to bikes, with not a painted line, but an actual physical divider (just a curb thing. You can drive over them but if you do it at speed that might cause some damage, that's all. Cheap as heck, but an order of magnitude better than just a painted line of course). They are wider than 'the minimum necessary for the width of one bike' that you often see elsewhere.
A select few tricky intersections have dedicated bike infra. Maybe one bridge is bike-dedicated.
And that is all. That should fill you with hope: __That is enough__ to get the kind of bike-friendly name that Copenhagen enjoys. You can get that done in any major city on an acceptable budget within the span of a decade, assuming non-deadlocked political chaos (unfortunately, US and UK, you may have to return to that feeling of despair). From _there_, by all means, look at The Netherlands as bike walhalla.
Here's a simple formula to 'fix' the stroads of the USA. They tend to be 4 to 5 lanes each side, so there's plenty of room for this:
1. Turn the stroad into a road - few exits (no way to turn right onto a store's parking lot). But only 2 lanes. Reducing 5 lanes to 2 sounds like a disaster but it won't be: Road congestion primarily depends on the exit: If a popular destination cannot deal with the number of cars that want to exit off of it, even if you have 100 lanes, you _will_ end up with a traffic jam eventually. 2 lanes still allows dynamic traffic (faster traffic capable of passing slower traffic). That's 90% of the win right there, any further lanes barely make a dent.
2. Make strips of 'access road' - these are small, 1-lane roads with a low maximum speed, where every few meters an 'exit' to a store's car park or a home driveway. Between the access road and the main car road there's a real divider: A ditch, a small creek, or an actual metal divider if you have to (Especially in the US with all the trucks, I fear folks will just drive across the dirt or grass otherwise). If you wanna throw money at it and really work on making the place look nice: Line of trees does wonders. Only way to switch from the main road to the access road is to exit onto one from the major intersections which are now miles apart. Between 2 intersections there __are no exits at all__ on the main car road. To go to a store you drive to the intersection that precedes it, exit onto the access road, and drive to it from there.
3. We have 1 lane left (2 lanes to the car road, 1 for the divider, 1 for the access road). The remaining road can now be used to become a bike path. It should optimally be between the access road and the main car road, _between_ the trees : You don't want the bikes to have to deal with the exit/entries onto driveways and car park every few meters. You have plenty of space: in this setup, assuming you started with a 5-lane stroad, it's 2 lanes worth of space you get to play with.
It's not exactly cheap but the US is spending literally multiple billions on widening literally 26-lane-wide highways (Katy Highway for example) with some more lanes to 'fight traffic', which seems idiotic and indeed does not work - if you want to fight traffic, reduce traffic. One way to do that: Entice some car traffic to turn itself into bike traffic by making that a viable option. You won't, and can't, replace all the traffic. But if you can eliminate even 5% of the cars, traffic jams are reduced by 50%+. Building these bike strips and turning massive stroads into roads+streets is an order of magnitude cheaper.
Note that the primary problem is that the popular target exits lead into city blocks that simply cannot handle the traffic, hence, 'widen the highway' is a net negative, even: It makes people _think_ the car is now a better option (induced demand), but it didn't do anything at all to address the problem. So you really just need to add some bike infra to these overly busy destination city blocks to replace 5% of the traffic within them with bikes - just the 'local traffic' will easily do that. So, this WILL work.
And yet, it isn't done. What the fuck, USA?