Semi-Circle Turnaround vs Single Point

winstonMember

I have a client wanting a put a 5k course on about 40 acres of land. Half of that is a baseball stadium, the rest is parking lot and a short service road that does not go around the stadium. I see no alternative to creating multiple out and back segments (spurs) or run circles around the parking lot. I measured it point to point but considering the creation of 180* semi-circle turns instead of the single point. BTW, there are 6 total.

I would appreciate any feedback for the following questions:

Q1: Given the availability of at 20-foot-wide area, curb to curb, what would you consider the optimum value for the radius to the outer perimeter of the cone arc?

Q2: If I map the course with single point turns, and provide detail on a supplemental page for an option to convert one or all the points to semi-circle turns, will this pass muster? Has anyone done this on a certification before? The client has an experienced timer and course setup manager so I feel confident it will be set up correctly either way.

Q3: Is it worth it? Even a small semi-circle turn would make for smoother turns and a better experience given there are several. As for safety, I have seen runners slip and pile up going around a single cone. Maybe a 10-foot-wide semi-circle would be safer. Any thoughts?

4/30/223:22 PM

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jimgerweckMember

Here’s how Bob Thurston laid out the turns for the UpDawg 10 mile course in DC. He’s done the same for Cherry Blossom 10 mile. It can be documented on the cert map like start finish detail.

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5/1/228:38 AM

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AdminMember

There is a discussion of turn-around layout and descriptions starting on page 24 of the new version of the Procedures Manual.

https://docs.google.com/docume...xQU/edit?usp=sharing

Nothing wrong with including two descriptions of the turn-around. One for a single-cone TA and one for a semi-circle TA.

5/1/2211:43 AM

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Race Resources LLCnew member

Documenting a turn-around arc doesn't seem to me to be necessary. As long as the TA point is documented, the course layout team can set up a semicircular TA as in the image Jim posted above. As long as everyone runs around this point, they aren't shortening, they are slightly lengthening the course, "of course". Some runners naturally take this kind of an arc at turn arounds - particularly faster runners.

In the 1983 Cherry Blossom 10 Miler, Greg Myer tried to turn too sharply at a single point TA. He fell and opened a gash on his leg. It was astonishing to see him run past everyone with blood running down into his shoe. He still set the American record for 10 miles that day. 8 days later he won the Boston Marathon.

5/3/228:17 AM

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AdminMember

What you say is true. But if the RD is going to set up a semi-circle TA, you might as well tell him how to do it without adding distance to the course. Below is an example from one of my maps.

https://www.certifiedroadraces.../?type=m&id=1593

It's really not even necessary to provide a diagram of the semi-circle. You can just say in your description where a single-cone TA should be placed, and where the center of a semi-circle TA should be placed (like I did in the mile mark descriptions).

5/3/228:36 AM

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Race Resources LLCnew member

I see - it does make sense to show it that way to aid the course layout team.

5/3/228:38 AM

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