It's not about bringing jobs back, it's just expensive. Building a 10 mile road in the middle of nowhere can easily cost 20+ million with a bridge or two, and take 3 years to build nowadays vits not like in the 60s where you could just lay down dozens of miles per road, per crew per year, while killing the entire ecosystem where they are working. Building in a city? Even more expensive. This is why they generally don't build roads in cities anymore. They just patch up old ones, maybe add a better intersection. It just costs too much. If you want to build a bypass through a city this could easily become a multi decade project taking a chunk of the states entire GDP.

For one small crew you are looking at about 60k-80k for skilled operators per operator, and a crew needs 2 or 3 usually at least. This is in low CoL areas. You also need about 5 or more laborers, which is around 40k a year, a supervisor which is around 80-120k a year. So in labor costs you are looking at let's say 600k per year just in labor costs, this isn't including the state workers and inspectors, which will probably double that cost so about a mil per year just in labor. The machines are on average probably 250k each. Let say that a company has to replace 2 or 3 per year and does 3 jobs per year, that's an additional 250k.

So 1.25 million.

The engineers are probably going to charge at least 100k plus labor so maybe add about 300k over the life of the project about 2.5 years. This is 1.35 million. Running 5 machines a day at let's say 75 gallons of fuel each per day, is let's say 1500 a day, times 365 is about 50k a year in fuel to run 5 machines. Maintenance is hard to estimate but it's probably around 250 a month per machine. Thats about 3k per year per machine and you have 5 so that's 15k per year for this one crew. So maintenance and fuel costs is about 65k per year, we are at 1.5 mil with occasional large repairs like engine swaps and tires, and we haven't even considered the material and hauling costs or asphalt or grass and signs and everything else which is most of the real cost. With the materials, on a 2.5 year job, I would reckon it would be about 5 million dollars in hauling plus a 15% profit margin, 4 million in asphalt, 50+k in seed, 250k in pipe, 1-2 million per bridge. You quickly get up to around 15-20 million for even small projects.

Now build that in a city and you easily double the cost or quadruple it. You have to buy the land at near market price, you have to haul off the waste. You have to reroute water and power and sewage and gas lines. You have to build temporary reliefs so traffic can still flow. You can only work in certain hours in order to keep traffic moving while it's the most busy. You will destroy roads by hauling millions of tons of material in and out which will eventually have to be repaired. It's a miracle that any construction work gets done in cities these days with all the complexity and regulation and costs associated with it. That's why it mostly doesn't happen. It costs too much, it's too much of a headache, shutting down some roads will just completely destroy a city and the local economy for years because of traffic. There is so much stuff in the ground that it's hard to dig anywhere without causing hundreds of thousands of dollars of damage. It's a real nightmare and it only works because dozens of people are delegating tasks which they are experts in, but even this class of people is disappearing because the pay is so low for the amount of work, and the stress is high. Being skilled at that kind of work takes years of experience, yet most of the people they can hire these days tend to be drug addicts and stuff because the pay is so low. They stay for a year and leave because the job is hard, the hours are long, the equipment sucks, especially with the def systems that blow piss in your face now, and dealing with subcontractors is just a nightmare because nobody can build anything within spec anymore. Things have to be done over and over to pass inspection and subcontractors know that they can try to avoid responsibility and make you sue their insurance company after the job overruns and you get penalties as the prime contractor.

It's not as easy as just throwing money at the problem even if you have money to throw at it. There is a lack of skilled workers because inflation has been destroying working class wages which means any job that is hard to do is undesirable. The only thing that makes someone want to work 10-12 hours in the sun in the mid all day is good money. Since the money hasn't been there for over a decade, there is a big gap in skilled labor for this type of job. Most of the old folks are starting to become cripples, there isn't much in the way of middle aged experts in this stuff. Theyd rather go work a much easier job, for 10-15% less pay and just see their family and not have a terrible life on the road, and work reasonable hours and have breaks and downtime. Companies aren't going to pay more because the only thing that will overcome their greed is state requirements for minimum pay for certain roles, but with the increasingly Republican and liberal politics, those wages are way below what inflation has been so in reality workers just don't care for that type of work.

Unfortunately there is nothing you can do about it. Society will just degenerate, the rich will become apartheid, American cities will just become 3rd world countries. Politics will swing back and forth between far left and far right economics, equally as stupid. There is no way to save it until it just collapses and people learn some humility and the weak die off so life can prosper again.

at least five stations.

This, but we need 4 lanes dedicated bus-only. Two for "local" busses that stop at every station (in both directions).

Two more lanes (in both directions) for "express" busses that only stop at a few major stops with transfers.

It does because you have to have the capacity for cars first, and many cities are already under built for the amount of traffic you have there. You can't just take roads used for cars and convert them to bicycle only lanes in many cases because you will gridlock the entire city in traffic if it isn't gridlocked already you cant haul 30k lbs of food on a bicycle. These roads are like the arteries of civilization. Modern cities can have more then a million people living in them and they all need resources to survive as well as they need to be able to commute to survive.

It's also a compounding problem. The more traffic backs up, the longer it takes to merge and turn, the slower people drive and the more stressed people become so they highly the passing lane and stuff. In a city some places can be a bottleneck where a single bad accident can bring 80% of the traffic to a stop within minutes.

There might be ways to do this stuff but it's not necessarily as easy as just converting roads to bike lanes unless you are in areas that don't have a lot of traffic. Some good solutions are things like requiring that new builds keep a minimum distance from the roadway so that you can easily expand in the future. Building new expressways to relieve pressure on other roads so you can utilize them. NonE of these are quick or easy or cheap.