I don’t know if this topic was treated in the past but I think could be interesting to discuss.
I’m looking to a solution that allow me making estimation or determination of the “capacity” of a road race, means determine how many runners can I have on a road race.
I’m in the organizational team of the Ticino Marathon (www.maratona-ticino.ch) in the South of the Switzerland, where since about 20 years we have an average of 1’500 runners. Due to the geographical position we have not a lot of possible variants for the road race and also the road used has some limitation on the width.
Often we must also use some road in both direction.
View the trend of the last years we are increasing the number of runners and we would like to know where could be the limitation of the actual road course, in order to plan eventual deviations or modifications.
Any idea?
Original Post

The route seems intelligently designed. Basically it consists of a double-loop course, about 10 km from one end to the other, with much of it having runners moving in two directions. The fast runners will have no obstruction until they complete the eastern loop at 7 km, and at that point the slower runners will already have passed the point, as it is only 2 km into the course. The front-runners will then have a clear road until they reach 16-20 km or so, when they will encounter people going in the opposite direction. These people will have run 10-12 km and should be spread out. During the latter part of the second loop the front-runners will be constantly catching and passing people. They may have no trouble doing do, but the lead vehicles require more space, and I would think they already have had some problems here. Perhaps they will need motorcycles to shepherd the slower people to one side so that the lead vehicle and fast runners can pass.

What is the ultimate capacity of the course? This is best determined by examining past performance. Last years race had about 1800 runners. Were there complaints? Did the traffic people have trouble keeping the runners sorted out? Was there too much congestion in the middle of the pack?

If there have been no serious problems, it looks like the field could be safely increased to 2300 or so. This may happen by natural growth of the race. Some races find that they reach a certain size and stop growing.

One answer, of course, is to make the course one large loop, with running in only one direction,but it’s been said that this is not desirable. Part of the route – the waterfront – would be reduced and replaced with something less attractive.

I don’t think there is one perfect answer to this question. The people who operate the race have the best information to make choices.

The course seems well-suited for a good half-marathon. Doing it twice is possible, but I think overall quality is lost in an attempt to make a marathon out of it.
Last edited by peteriegel
As I know, until now there weren’t important complaints.
Except “congestion” on crossing some main route where car’s traffic should wait many minutes, and minor problem (obstruction) when first runner are crossing the big group of runners in the road race with both direction (i.e. km 7).
Maybe this can be optimized introducing specific signalization and more lead vehicles (usually motorcycles).
Your impression that the course seems well-suited for a good half-marathon is correct: and this is supported also by the trend, where the runner of the half distance are more than 2/3 of the total runners, but as organizer we would like also to maintain the Olympic distance of 42.195 km.
And of course our expectative are not to have similar number of runners like NY marathon .
I will discuss this again with my colleagues, maybe there are the space to improve again the quality on optimizing the race leading and guidance.
I’ve another question related to course measurement but I will open a new topic on the forum.
I find that very interesting data can be obtained from electronic scoring systems. I have feed the prior year results into a database, group by finish time, and print a graph. This gives me the volume of runners crossing the finish line over time. It provides a good idea of how much processing capacity and room the finish line needs.

Each race has a different profile, depending on the number of top runners at the front or social walkers at the back.

Using the volume from last year I can also project the volume, or rate of passing runners, at any point in the race. A Max runners per minute graph for a waterstop will give you some idea if it will be swamped. (Here the courses are flat so you I can project finish times back to prior points.)

If the course has bottle necks I can project how much the race has thinned out by that point, and if there will be enough space on the road.

I think the other problem is that people often don't factor in the bottle necking caused by right angle corners or abrupt changes in grade.

Processing per minute is a good way to talk to RD and race comities.