On this note, I have always wondered why new-towns aren't like this.
Every time you run a road, stick a tunnel underneath, or beside it. Or one tunnel each side.
You have to run, presumably, at least sewers, electricity, gas, water, street lighting, traffic control, telephone, Internet etc. already so why not build it all in and put a tunnel through it too.
Done properly, you'd never have to dig up a road to get to the services you require and all maintenance can take place underneath the road.
Sure, it adds to the cost initially but it MUST save on cost within just a year or two.
And you instantly know that if you are on or near that road, it's trivial to hook in to any known service.
If we ever "started over", and I were in charge, I would enforce it. You build a road, path or other highway designated as public? Then you have to put in a large service tunnel, all the utilities (or capacity for them without disturbing the road) for the entire length of anything classed as "public highway" (i.e. a serviced street of any size).
Then your Internet connections are as redundant and routeable as your transport links, telecoms network, power distribution, etc. And just as you could "go around the block" if there was one particular road out, you could re-route all the other utilities (maybe not every time, because of capacity etc. but the majority of time surely?). And you'd not have to dig up a road except to MAINTAIN that road. Not every utility, service, pipe, duct or cable that might happen to be under it. And if you built the service tunnel properly and laid rail in it, there's nothing stopping you running a piggy-back service on your service routes to take the occasional train of parcels or whatever with you.
The Romans knew the road system was their best weapon - everywhere they went, they built roads, every time the road was too small to cope with traffic, they expanded it. No more different to how ants lay down scent and route to places. Why should we be having multiple, different, overlapping service networks at all? Stick them all together and then you know you can always put a box by the side of the road, don't have to dig up the countryside just to run a bit of power (if you do HAVE to, you certainly also need all the other services and a road that way too anyway!). And in the same way that roads join industrial, commercial, and residential, you can site your ugly equipment away from people's houses but still service those same houses.
I never got why we ever had one cable crossing over a street or not following the existing road network.