Due the fact that we will have in the next years the Swiss Championship of Marathon, we must re-certificate our road race, for this reason we will in the next months make a new measurement.
We have some doubt how are the right approach usually used to measure the race where we have a bi-directional road (runners will run this road in both directions).
The width of the road is often between 3 and 4 meters.

Solution 1:
The measure line (red) is equal for both direction, this assume that the runner can use always the shortest way.

Solution 2:
The measure lines are distinguish for the 2 race direction, and are parallel to the road's border.
No physical separation between the directions during the race.

Solution 3:
The measure lines are distinguish for the 2 race direction, and are parallel to the road's border.
Physical separation between the directions during the race (with obstacles like cones, etc.)
Complex to realize and also, due the limited width, the space for the runners are drastically reduced to the half of the road.

We will appreciate comments and suggestion to this topic.
Original Post
Solution (1) is the easiest for the organizers. They can set up barriers as they wish to, and they can change their minds. No matter what they do the course will not be short of the proper distance. It will be a small bit longer.

Solution (2) is not good for a championship event. The runners will run a shorter distance than the measured route.

Solution (3) has the advantage of separating the runners. I do not know whether the width of the road is enough. If the runners are separated, the route should be measured as shown below:

Suggested measure line for solution (3)

If only fast runners are in the race, the field will be small, and no problems with passing slow runners. If the championship is held as part of a large race, traffic control will be more difficult.
Last edited by peteriegel