Ultimately it depends on the cycling culture in a place and a lot of that depends on whom cycling is available to. If it is more accessible you will probably find people acting more sensibly and more like pedestrians.
A mixed use trail can provide refuge from busy roads. This is much more important if roads are awful for cyclists and I this can often be the case in some parts of the world. If roads are good for cyclists then the obnoxious people who would otherwise endanger those on the trail will be happier going faster and straighter along the roads. But they will only get better if cycling is more popular which will only happen if it is more accessible.
I think mixed use paths are not particularly bad and are also necessary on the way to better infrastructure.
Calling them bike infrastructure is like calling a school zone with zebra crossings and speed bumps a highway.
They are what should be built first though, because you don't get new cyclists without low speed, safe, fully separated bike infrastructure. They should always be paired with a nearby road with a cycle lane and somr plan for separated infrastructure though.
The separated bike lane *and* the mixed use path is the end goal, but if the immediate goal is to save the city money and make people healthier rather than create conflict and negative sentiment towards cycling, then you need a separate route for ebikes and more experienced commuters. Sharrows or magic paint suffice for this (at least temporarily) with adequate traffic calming or if the main car flow has an alternate route.
Imo, American negative sentiment and aggression toward bicycles is way more about politics and assumed demographics then anything else. It does not matter how well behaved average cyclist is. It does not matter how intrusive or safe it is. The people who are aggressive will focus on that one minor infraction that happened once to validate their anger.
I think we overall agree, but there are many things that can be done to reduce conflit points.
Firstly I agreed that the mixed lane with a shared car/bicycle alternate route should come first (as this covers both short/slow speed trips and high speed/high confidence trips), but secondly the shared lane has an absurdly small cost. Under 5% of the space and an even smaller fraction of the money spent on roads will give you a world leading bicycle network, and if you build it, it will be used -- cycling on good infrastructure is simply so much cheaper and more convenient than car ownership and cycle lanes have so much more capacity than roads that it becomes a no brainer.
I agree that bootstrapping it to get the political will needed for that pittance is extremely hard, which is why we need to think very carefully about encouraging long distance commuters who must average over 15km/h to make reasonable time and people taking the pram for a walk to mix. Ebikes are a big potential issue because they are both fast and favoured by new riders. It will only take one ebike with the speed limiter removed accidentally injuring a kid and hitting the news to set back bike infrastructure in an entire country by years.
Step 1 is mixed paths connecting local destinations (schools, shops, church, etc) and start reserving your space for the separated bikeway
Step 2 is a fully connected network where all the mixed paths have an alternate route with magic green paint or sharrows for high speed trips and to handle congestion.
Step 3 is build the separated paths.
You can't skip step 2 or avoid thinking about step 3 until it is too late.
Additionally throughout this process you need to fix all the cyclist and pedestrian hostile signals (waiting for a full 5 minhte cycle at a one way street full of stopped cars because the button wasn't pressed is absurd) and provide some alternative to stop signs (carefully designed roundabouts, yield signs, or cyclists-yield laws with public outreach work okay).
It is already difficult to have a car near house where you live here.
You complain that bike lanes are not used "enough", but a single parked car forces a whole lane to have a throughput of 0 commuters per hour. A bike lane that gets a single cyclist per hour is infinitely more efficient!
There was not enough space for cars, we tore down entire neighbourhoods and blasted through bedrock to create highways.
There is not enough money to fund a moon program or fix climate change, but when time came to bail out the banks, if you stacked that money as 1-dollar bills it would reach the moon.
There is not enough money to Fusion research, but our fossil fuel and airline subsidies in one year are greater that all-time fusion research budget.
Priorities.
The prioritization back then was that "those people" don't matter. That is how those were build.
Especially in the US there is plenty of space you can take away from cars, both lanes and parking.
The Netherlands did not knock down and rebuild Amsterdam to build bike paths. They took space back from cars.
The first is car centric, with lots of roads and deep set backs. These cities are amenable to bike and public transit transformation in terms of space, but usually have political resistance to change. These cities will be the easiest to add extra bike infrastructure to, once a political mass is reached. My current city is like this, and the current bike path master plan is trying to add enough paths for 96% of the city to be near bike infrastructure (currently it’s 10%).
The second category are really dense, and do not have the space for any extra lanes. But these cities dedicate a huge amount of space for parallel parking. Theoretically the city could remove parking for bikes, but practically this means purposefully pricing people out of car ownership, which is obviously unpopular. These cities should focus on public transit, which is by and far the most space efficient way to move people. For a lot of these cities this is less about installing new lines, which is expensive, but about making the existing system feel cleaner and more dignified. It will always be hard to make improvements when even the crappiest sedan is considered a step up from taking the subway to work.
The key is that cars don't belong in most places anyway. A residential street can easily be design as a 10mph one way cobblestone road with calming measures, freeing up the "other direction" side of the street for a 2-way bike lane and expanded sidewalks. Larger roads can be redesigned similarly for bike/transit with cars filling in particular niches like delivery of bulk items, etc.
It also costs less to maintain, kills fewer people, massively reduces healthcare costs improves the local economy and is far nicer to live next to.
There is plenty of money, most places are just directing it to yet another road widening project that will make things worse.
In any case, it's pretty much a non-starter to prohibit at least conventional bikes or pedestrians even though, on the more crowded and narrower paths, I'll avoid them during busy times as a walker.
https://www.insidenova.com/news/arlington/w-od-trail-effort-...
A bike-friendly infrastructure is based on three separate networks, for pedestrians, cycles and cars. Each of the three networks must be continuous, reasonably complete and able to stand on its own.