There has been a gas leak there for ages, way before the resurfacing. In fact im suprised that none of the locals reported it.

Was sad to see a new road get dug up so soon, but better than a bloody big hole being blown in it. Could be a number of reasons for it being left open. I would suggest contacting the contractor on the number on the roadworks for more info.

Could be venting gas, could be waiting for another utility to do some work etc.
Either way, its shocking to see how people are avoiding the closure by driving over pavements and ignoring no right turn signs.