Not that we will have to worry about it or anything but what will this be like in another 50 or 100 years. There are going to be so many abandoned lines underground.
A couple years ago, I called the water company due to chronic low water pressure. They determined that the service line from my house to the main had a leak. Of course, since our mayor sold the water company to a venture capital outfit, service lines are now the homeowner's problem (it used to be the water company's up to the water meter, whether the meter was inside the house or outside in a pit).
This is on the Thursday afternoon before the July 4th weekend, and I have no water
As part of the festivities, all of the utilities came out and marked where they thought their lines were. Seeing the gas company guy looking at a blueprint, turning it upside down, shaking his head, and spraying 2 lines on the street didn't exactly fill me with confidence.
On a related note, I have a fiber optic cable between my house and a former employer about 1/3 of a mile away. Most of this is up on utility poles, but a piece across a major road is underground. When we installed it, we registered it with the utility locating coop. We also gave the local cable TV company use of one of the spare conduits.
Whenever anything gets done to that road or the cross street nearest to it, lots of stuff gets marked
except these conduits. For about 10 years I'd go out and mark it myself if I saw new markings for the other stuff. Eventually I stopped bothering, as I'm not using the fiber for anything critical and I don't have cable TV any more (switched to satellite a long time ago).
This is nothing compared to the problems I have in New York City - no matter where in any street you dig, as soon as you get past 12" deep you're going to hit something unmarked. Even if you dig out the sides of a rectangular hole by hand, if you use a digger in the middle of the box (when you didn't find any lines on the edges) you're likely to hit something. Possibly several somethings. To give you an idea how tightly things are packed underground, the outside bottom of the Holland Tunnel is only 15" from the outside top of the PATH tunnel. Yup, fifteen inches.