Does the way in which a road is constructed favour left-hand side or right-hand side driving?

With the possible exception of pavement section strength requirements, there is no difference. The road is designed to be strong enough to hold the proposed traffic load and to drain water. A standard 2-lane road (one lane of travel in each direction) will have a crown (high point) in the center and will slope down to either edge to properly drain the pavement surface. It is much easier to drive on the left in a right hand drive car (steering wheel on right side of the car).

The end result should not be any different.  As far as the construction process, I wouldn't say it favors one over the other.  I need to think this through though as far as whether there are any differences.For the most part, I think construction of one would just mirror the construction of the other.  Most of the time when we are constructing a roadway, we need to keep some lanes open to traffic at all times.  We generally phase, or stage, the work in order to accommodate traffic.  This should only be different in that one mirrors the other.As far as construction vehicles, the on-highway vehicles, like dump trucks, paint trucks, and the like will be configured for whatever side they are supposed to drive on.Paving machines should be about the same.  Rollers, backhoes, and excavators tend to have the cab in the center, so this shouldn't effect anything.Cranes may have the cab on side or the other, but this is not going to change how they construct anything.  I don't really think there is much difference in how it would be constructed.

Having just spent the week in Singapore, what I kept noticing was it felt very inefficient compared to driving on the left-hand side. The driver would constantly be having to go in a big circle to make a turn into a particular hotel or office park (if we were driving on the right-side, it would be 1/4 of the time). But it logically didn't make sense to me that it would be more inefficient and I assumed it was the jet lag talking.  Would love to hear more on this.