When it’s safe to do so, switch sides of the road throughout runs so that the same leg isn’t always a little lower. Running like that too much can tilt your pelvis and set off a cascade of undesirable compensations. Running both and against traffic is safest on roads with wide shoulders on runs in daylight.
On a particularly sloped road, I’ll run toward the middle if I know it’s a road that doesn’t get much traffic. On those quiet roads, your acquired runner’s hearing will alert you in time that you need to get over to one side.