eli5 why are manhole covers in the middle of the road and not on the sidewalk?
There has to be a better way. Why not put them under the buildings ? Obviously doing that retroactively would be extremely difficult and costly but when designing new cities why wouldn’t the utilities be placed in line underneath the properties ? Then there could be access points on the sidewalks and of course the utilities would have to cross streets but they would be under every single part of every single street, just part of one spot of streets like a crosswalk
In the UK, they are both in the road and on the pavement (sidewalk for you silly sausages across the pond)
Some might have been initially on the side of the road, but if the road had been widened, altered, or lanes added, they would no longer be on the side of the road.
Also, there are several different utilities trying to use the same right-of-way. You could have water, sewer, drainage, electrical, and communication all having their own infrastructure in the ground. All would have their own manholes for access.
Also, in larger cities or communities, if a conduit system filled up then extra manhole systems would be added in whatever space was available.
And lastly, it depends on what is under the ground. Utilities will not want to blast through bedrock or ledge and will prefer to place their infrastructure in soil.
I’ll do you one better, WHY are they called manholes? XD
Because they are used to access utilities like sewers or gas lines, and those are located in the middle of the road.
They aren’t ALWAYS in the middle of the road, sometimes they might be under the sidewalk. But a lot of the time they are in the middle of the road because this keeps them an equal distance from the houses on each side of the road which all need to use those utilities. Also, these are publicly owned services which city workers may need to access or even dig up for repairs. It is best if they don’t need to go onto or damage people’s private property to do this, and a sewer under a sidewalk for example would either be very close or actually overlap with people’s buildings or front yards.