Uerthane and mark each individual one- might take some extra work to mark them and map them, but it will be worth it in the long run. I would also talk to who ever the contract is for and advise them that you will be going around them- especially if they are raised up like that. Just out of curiosity- how high are they raised from the current road surface? I'm assumiong about 3/4 to 1" if it's typical road construction - there is usually 3/4-1" of topcoat over the binder in my area, and that hieght will wreak havoc on any plow. One of the gas stations I do has raised rings around their tank fills, and they are tapered, but even with my trip edge I hit them pretty hard, I usually end up back dragging over them a few times unless we've gotten enough snow to fill in the voids around them, then I can go over them straight until they get cleaned out and melted off agian.
Urethane will definitely cushion the blow- but if they are over 1/2" high, mark them, make a map of them- you will have to replace the markers during the season, almost gauranteed- and plow around them until you have enough of a base built up so that you can plow over them.
Bill