> The solution is to make everyone fully aware of the rules.

Unfortunately, "everyone just do a better job" is generally a failing strategy. This is also the problem with getting drivers to do a better job. They just won't, at least not without a lot of effort.

> Again cyclists take the blame for all of the problems, while still not being provided with any solutions....

That's because cyclists are the problem. All the things you describe about pedestrians apply only because bikes showed up on sidewalks. Pedestrians weaving side to side and wearing headphones are only safety issues if fast-moving vehicles are sharing the path. It's not that pedestrians are immune from fault. Pedestrians who wander into traffic randomly are considered at fault. But they aren't at fault for acting like pedestrians on a pedestrian path. We don't put cars and pedestrians onto shared paths and then expect pedestrians to walk in perfectly straight lines to allow cars zip past them at 20mph.

And there is a solution for cycling, which is to make roads safer for cyclists. There are lots of ways to do that. There isn't a lack of ability, but a lack of will and funding.

> The problem with putting in separate bike paths is now we have three different road systems sharing the space, which in cities is often limited and in rural areas is economically unfeasible to maintain. And it still doesn't solve the problem of cross streets, which both pedestrians and cyclists suffer from at the hands of motorists.

Yeah, it's tough to share the space efficiently. Dumping the problem on pedestrians doesn't fix it, though.

Pedestrians also don't have as much of a cross-street problem as cyclists. This is a place where pedestrians tend to pay attention and cars tend to look for them. Cyclists have a much bigger problem because 1) cars aren't looking for fast-moving vehicles on the sidewalk half a block away, 2) cyclists can't stop at a moment's notice when they realize the car isn't going to stop.

> Maybe the answer is to draw a line down the sidewalk to indicate to pedestrians and cyclists that they need to stay to the right (or left depending on country) so faster modes of transport can safely pass.

This doesn't generally work. Pedestrians will cross the line whenever it's convenient to do so, or if they're not paying attention, or whatever. You could maybe make it work by making it extremely wide, but then you might as well have separate paths and physical barrier between them.

> Maybe we should enforce a speed limit on bikes in certain areas.

Good luck with that. Most bikes don't have speedometers and in any event, the safe speed on a shared path is far slower than most cyclists want to travel, namely jogging speed.

> But all of the problems pedestrians face at the hands of cyclists, cyclists face against motor vehicles, but the danger is far greater. Getting hit at 45mph while you're riding at 10mph is a lot different than being hit while walking by a bike going 10mph.

That doesn't mean that dumping the problem on pedestrians is a good tradeoff. Not only do mixed-use paths put pedestrians at higher risk, they still put cyclists at risk (possibly worse risk, due to the intersection problem), and they frustrate both cyclists and pedestrians. It's not a good solution for anyone except leisurely cyclists who can frankly cycle on sidewalks today and it's fine.

Also, bikes are often going faster than 10mph.