Conversely, if you are pulling a trailer on 2-lane rural or mountain highways, it's a lot easier on the people in passenger cars if you drive right at the 90 km/h speed limit, because then it's easy for them to pass you. If you speed up to 105 or 110, they'll still catch up to you, but it's much harder for them to get by. I've tested this in Alberta an BC and found that at 90, a line never forms behind me. Get significantly better fuel economy too.