Earlier quoted context omitted.
People drive on average 18 km/hour on a bicycle here (flat terrain). That is nowhere _near_ 50 km/hour. Racers drive such speeds, and they are aerodynamic, on a race bike, well maintained bike, etc. Our oldest is now 4, like I said she can barely bicycle as it is. Kids of age 8, 10, 12 they go to elementary school, and many go by bicycle. Sure, some walk too. After age 12 they go to high school, and these are more fa…
The low speed is precisely my issue. Sure, you can separate cyclists from cars on new roads, but it's not financially reasonable to rebuild the whole city trying to get people to move from cars (comfort) to bicycles (lack of comfort + physical effort + slow). I don't mind cycling focused cities. I've lived in one and it was nice, but it was also rather small so the size allowed for bicycles to make sense. Ain't no on…
Well, that depends on a lot of factors.
The size of the current roads might be one. If there's room, a bicycle lane might be feasible, but you can also have the cars as guest (which results in the same as you argue: that cars will have to adapt to the speed of the bike). This is the case with the smaller roads in very rural areas. Although I have even seen some roads become one way streets with bicycle lane. You can also combine bicycle lane on the same side which I've seen but then they're guaranteed separated from the main road.
20 km to work is a lot indeed, I don't want to do it, but I have a co employee who goes like 45 km to work (and then takes train back). I appreciate the effort. On electric bikes, 20 km isn't going to be a lot (if you assume 25 km/hour its slightly less than an hour), but we are not living in a world where these are dominant yet (as in the status quo).
I've grown up in a rural area, so I know I can go as quick as cars downhill. Even as kid. Its a cool feeling (I've yet to drive an e-bike), but I was glad I was on the bicycle lane I can tell you that. Also, I took risks at traffic lights and crossings. Risks I shouldn't have taken, tho that's what youth do.
Now, if you want to make a 30 km zone and want to combine cars with bicycles, I give you a pass. Because I have seen such in action. Although sometimes the cars cannot go 30 km/hour it allows the two types of vehicles to live more in harmony. I live in such a zone, though the delivery men tend to disagree. Its a miracle they don't hurt kids with their buses.
There's also these vehicles which look like cars but they can go like 45 km/hour and therefore don't require a drivers license. You can see the elder with them, they're used on the bicycle lane, though they take a lot of space. That's the issue here: space. We only have so much and we want to fairly share it while stimulating the right type of traffic. Cars are inefficient in that sense, therefore its OK if we stimulate other types of transport by making them less attractive (higher fuel costs, higher taxes, less space for them, higher parking costs). These are already happening here as it is. The fuel costs are higher due to war, and certain inefficient fuel types of cars (I don't know the details) aren't allowed in inner circle of city anymore. Parking is expensive. All of which stimulates public transport, bicycle, walking, and electric cars (which are basically only for rich people as it is). Its going very slowly though as those who drive cars are a large amount of votes who also are the ones who vote for certain politicians. These chicken-egg problems as well as lack of popularity of bicycle hamper change.