How to Easily Determine A Track's Turn "Tightness"

[Charley Shaffer]

Here's a simple way to determine whether a track is IAAF standard or if it has tighter or wider turns than standard. Recent misstatements by prominent TV commentators, former USATF officials, and prolific bloggers have made it apparent that this remains a subject of confusion to many.

An IAAF standard track has a turn radius to the measure line in Lane 1 (which is 30 cm out from the outer curb edge) of 36.80 meters. It has straights of 84.39 meters in length and turns of 115.61 meters in length. This design has been used for all Olympic Games since as least as far back as 1976.

First, you need to verify that the finish line is at the very end of the home straight. That is the usual setup these days.

Next, look at the beginning of the home straight. On an IAAF standard track, you will see that the point where the final turn of a 400 ends and the home straight begins is about 6 meters nearer to the finish line than the markings for the end of the 4x100 passing zone. This is usually easy to see, from anywhere on the home straight side of a stadium, even from the finish line seating area.

If the straight does not begin until, for example, about 15 meters past (as the runners run) the end of the passing zone, then you have a track with extraordinarily wide turns. Examples include Zurich (Letzigrund), Brussels (King Baudouin), New York (Icahn), and Burnaby (Swangard), all with approximately 75 meter straights. Their turn radii are approximately 40 meters to the measure line in Lane 1, making their Lane 1 roughly equivalent in tightness to running toward the outside of Lane 3 on a standard track.

If the home straight begins at or before the end of the passing zone, then you have a track with tighter than standard curves. Examples include Stockholm (Olympic) and Sacramento (Hornet), both with approximately 90 meter straights. These have turn radii of approximately 35 meters, meaning that even their Lane 2 is somewhat tighter than Lane 1 on a standard track.

That's all there is to it. There is no excuse for guessing or passing on superstitions.

[Charley Shaffer]

Appendix

Some older track configurations, still common at many colleges, have even tighter turns, often with 100 meter straights, putting the beginning of the home straight exactly in the middle of the passing zone. These are known as "equal quadrant" designs, having straights and turns of equal length. The old pre-1988 Hayward Field 440y configuration had an even tighter design with 115 yard straights and 105 yard turns. Lane 6 on that old Hayward track was tighter than Lane 1 on the present, IAAF standard, Hayward track, yet 3 Olympic Trials were held on it.

If the finish line is past the finish line into the first curve, as it is in Lausanne (Stade Olympique de la Pontaise) or as it used to be before 2005 in Oslo (Bislett), you must make adjustments in your calculations. Also, if the finish line is somewhere on the home straight, once common at many high school tracks, adjustments must be made.

[DJG]

Thanks Charley for the clarification. And on any of these tracks does a 200 runner in lane 8 run
a shorter distance on the turn than the runner in lane 1?
Or as one TV commentator says "Lane eight always gets to the straight away first."

I believe you can put the Jesse Owens Track in Columbus, O. in the extra-wide turn group.

[rsb2]

I think the easiest method is to measure the length of the 400 m. stagger difference, from lane to lane, plug it into a calculator, use the basic C=pi(d) formula, and you can very quickly determine the length of the straights and curves. Remember, of course, that the lane 1 measure line is, as Charlie said, 30 cm. into the lane, and not 20 cm., as it is in the other lanes.

[Conor Dary]

I think the easiest method is to measure the length of the 400 m. stagger difference, from lane to lane, plug it into a calculator, use the basic C=pi(d) formula, and you can very quickly determine the length of the straights and curves. Remember, of course, that the lane 1 measure line is, as Charlie said, 30 cm. into the lane, and not 20 cm., as it is in the other lanes.

The stagger difference from lane to lane is irrelevant, except for lane width. No matter how 'tight' the curves a track is 2 semi circles with 2 straights.

[gh]

the finer points of geometry have always escaped me (totally), but don't broken-back tracks not have two semicircles?

googling found this test:

<<A high school has just built a new track. They have hired you as the consultant to determine how much sod (measured in square yards) is needed to completely cover all the area of the infield that is enclosed inside the inner edge of their broken back running track. Since sod consists of pre-planted sections of grass turf, you need to estimate the area of the infield enclosed by the inner edge of the running track.
A scale plan of the track will be handed out in class.

Some running tracks are constructed to enclose a football field in the center. In the majority of these tracks, the curved ends are arcs of a circle. However, a “Broken Back” or “Double Bend Track” is designed to enclose a soccer field, which is wider than a football field. The broken back track has a 400m or 1312.34 foot minimum total distance, measured along the measure line of lane one. The track consists of two straight sections of equal length and two curved ends that are not arcs of a circle. Rather, each curved end is created using curves with two different radii. This design creates a more square shaped track with shorter straight sides, allowing for placement of a soccer field inside.

In fact, broken back tracks can be made with different choices of radii, so that broken back tracks are not all identical. Building guidelines suggest that the radii be marked with a permanent marker erected near the track when it is constructed, so that the information about the radii will always be known.

[Marlow]

the finer points of geometry have always escaped me (totally), but don't broken-back tracks not have two semicircles?

googling found this test:

two curved ends that are not arcs of a circle. Rather, each curved end is created using curves with two different radii.

Further google find: (http://sportsbuilders.org/press/track_f ... _lores.pdf)

With the initial growth of soccer, the double bend track, formerly known as the “broken-back track,” became popular. It has a compound radius curve at each end (usually two small curves and a large curve formed by three different radii and together forming one complex curve with a major bend not to exceed 60 degrees).

[Conor Dary]

That all is interesting. But there is no international track that is not 2 semi circles and 2 straightaways, which is what we were talking about. For one thing a semi circle has constant curvature.

As for putting a straight in the middle of a curve, that is not too hard. 4 quarter circles with straights in between of any length you want.

In that ad, every picture is of a standard 2 semi circle track.

Anyone have a photo of one of these tracks? They sound fairly complicated and the possibility of error higher than a simple 2 semi circle track.

[rsb2]

So, Conor, let's see if we are talking the same language. Given that we are not talking about broken-back or double-bend tracks, and that we know the lane width, are you suggesting we can not calculate the turn radius, or the straight length, if we know how long the stagger measurement is in each lane, relative to other lanes. Surely that is exactly how the measurement is done, by knowing the combined length of 2 straights and 1 turn, and then subtracting that distance from 400 metres, and knowing how far "around the first turn" each staggered start point is, all based on knowing the radius, yes/no? I am definitely not a surveyor or geometrist, so what am I missing here?

[Randy Treadway]

I always thought all we had to do was go to the end of the straightaway, measure straight across the field to the beginning of the backstretch straightway, and that's the diameter of the semi-circle.

Broken-back tracks or whatever you just said, where the curve is half an oval instead of half a circle, make that impossible of course... but I'm hearing from one or two of you that ALL curves on the international circuit are half circles- just different radius/diameter.

WAY WAY back when I was in high school, I did train for a week during my spring break up in Ohio on a track that had four curves... on the two ends was a very short straightaway. I guess that's a broken-back in an extreme sense. The overall shape was very much like the Indy 500 race car track, but of course none of the curves were banked.

[Conor Dary]

So, Conor, let's see if we are talking the same language. Given that we are not talking about broken-back or double-bend tracks, and that we know the lane width, are you suggesting we can not calculate the turn radius, or the straight length, if we know how long the stagger measurement is in each lane, relative to other lanes. Surely that is exactly how the measurement is done, by knowing the combined length of 2 straights and 1 turn, and then subtracting that distance from 400 metres, and knowing how far "around the first turn" each staggered start point is, all based on knowing the radius, yes/no? I am definitely not a surveyor or geometrist, so what am I missing here?

Let us have a standard track with 2 semi circles and a fixed lane width. Then the staggers, i.e. where in a 400 meter race, the starting spot of each lane, is the same distance down the track from the start. That is because the extra distance run in that lane, say lane 3, is the same for every track, no matter the length of the straight or how tight the curve.

I presume that is what you mean.

[Conor Dary]

Broken-back tracks or whatever you just said, where the curve is half an oval instead of half a circle, make that impossible of course... but I'm hearing from one or two of you that ALL curves on the international circuit are half circles- just different radius/diameter.

They would have to be. Otherwise a change in curvature would require a change in a inward lean. That is just physics. I think trying to run 20 sec 200 would be impossible on one of these non-constant curvature tracks.

[Charley Shaffer]

I always thought all we had to do was go to the end of the straightaway, measure straight across the field to the beginning of the backstretch straightway, and that's the diameter of the semi-circle.

That would work, but I was trying to offer a suggestion for fans and broadcasters that could not or would not go down on the field with a 100m measuring tape. Eyeballing the straightaway length with the aid of the last passing zone can usually result in an estimate that is within a couple of meters.

[Charley Shaffer]

That all is interesting. But there is no international track that is not 2 semi circles and 2 straightaways, which is what we were talking about.

Correct, AFAIK.

As gh wrote, those "broken back" tracks are often called double bend tracks in the track-building industry. They are indeed allowed by the IAAF for WRs--see Rule 260.18(c), which refers to "where the bend is formed with two different radii . . . "

[gh]

Broken-back tracks or whatever you just said, where the curve is half an oval instead of half a circle, make that impossible of course... but I'm hearing from one or two of you that ALL curves on the international circuit are half circles- just different radius/diameter.

They would have to be. Otherwise a change in curvature would require a change in a inward lean. That is just physics. I think trying to run 20 sec 200 would be impossible on one of these non-constant curvature tracks.

I have this vague recollection that when the Indy track was first laid in the early '80s it was broken-back. Can anybody confirm? (it of course coughed up sub-20s)

[Conor Dary]

Broken-back tracks or whatever you just said, where the curve is half an oval instead of half a circle, make that impossible of course... but I'm hearing from one or two of you that ALL curves on the international circuit are half circles- just different radius/diameter.

They would have to be. Otherwise a change in curvature would require a change in a inward lean. That is just physics. I think trying to run 20 sec 200 would be impossible on one of these non-constant curvature tracks.

I have this vague recollection that when the Indy track was first laid in the early '80s it was broken-back. Can anybody confirm? (it of course coughed up sub-20s)

That doesn't seem right. The IAAF is quite specific on construction of a track.

http://www2.iaaf.org/TheSport/Technical ... Report.pdf

In the IAAF pdf there is a nice picture demonstrating what I have been talking about. And the caption below it reads:

Distance from the centres of the semi-circles...

But then this is all new to me. I have of course run on tracks that did not have the standard shape, but that was rare. And also didn't look terribly fast to run on.

[gh]

I'm guessing the IAAF didn't even have track-construction guidelines when the Indy track was originally built. And if they did, not sure that anybody in the U.S. would have necessarily felt obligated to follow them.

I think broken-back tracks were (and in many HS installations still are) far more common than you might suspect.

[jla]

That all is interesting. But there is no international track that is not 2 semi circles and 2 straightaways, which is what we were talking about. For one thing a semi circle has constant curvature.

Actually there is such an international track now - Helsinki! When it was renovated in 2010 they put in a "broken back" design with 24 - 48 - 24 metre radiuses in the bends. The straightaways became 98.52 m.
This created an outcry from the athletes in the first major event held there, the prestigeous traditional match between Finland and Sweden that autumn. The strongest criticism came from Finnish 200 m runner Jonathan Åstrand, but even the female 400m runners at their 54ish pace had major problems with the changes in curvature.
However, it was argued by the people in charge that the design was not breaking any IAAF rules and that it would be too expensive to redesign the track to a standard configuration (also they would need to take some 4-5 metres from the stands in either end).
Then this year the arena hosted the European Championships and suddenly athletes (other than those from Finland and Sweden who already knew) from all over Europe were shocked to find themselves on a non-standard track design they never before had experienced. Probably not even as kids.
The consequences became immediately apparent with a flood of out-of-lane dq's in the first round of the men's 400m on the first day. In the first heat three out of seven were dq'd! And the simple reason was a track where you were forced to re-adjust your running not only going in and out of the bends but also twice within each bend.
The athletes (those not already dq'd ...) managed to accomodate for this as the competition went on - but of course it came at an expense performancewise. In the 200m it was obvious that no one dared to run all out on the bend. Instead they ran "carefully" to avoid any mis-stepping (or injury) and then tried to pour it on in the extralong finishing straight instead. But some athletes - like Ndure - immediately cancelled their 200m entries.
Now that everybody know about this Helsinki will need to overhaul this design of the track to ever have a chance to in the future host any major international event in their otherwise magnificent Olympic Stadium.

[Conor Dary]

I'm guessing the IAAF didn't even have track-construction guidelines when the Indy track was originally built. And if they did, not sure that anybody in the U.S. would have necessarily felt obligated to follow them.

I think broken-back tracks were (and in many HS installations still are) far more common than you might suspect.

You are probably right. Especially in the HS category. What does the typical AD care about the shape of the track. Just fit in there. But 2 semi circles and 2 straights are so easy, relatively, to design and construct, that unless you are really tight for space I don't see the point.

Also the added complication to the design and construction of one of these tracks, seems ripe for error, without being extremely careful. Which leads me to think if these tracks are relatively common in HSs how many of them are mismeasured?

But as jia notes they are hard for sprinters to run on and I don't remember any such comments from the sprinters in 1988.

[26mi235]

A 24-48-24 curve is problematic in the 200 because the curvature is greatest when you hit your greatest speed.

I would expect that the change in curvature would initially lead to 'drifting' to the outside of the lane, possibly followed by an over-correction to running inside. It would also make for a more abrupt transition both entering and leaving the curve. Do runners start curving early and then run into the line when they hit the longer-radius middle section?

[Conor Dary]

A 24-48-24 curve is problematic in the 200 because the curvature is greatest when you hit your greatest speed.

I would expect that the change in curvature would initially lead to 'drifting' to the outside of the lane, possibly followed by an over-correction to running inside. It would also make for a more abrupt transition both entering and leaving the curve. Do runners start curving early and then run into the line when they hit the longer-radius middle section?

With 2 semi circles, the tangent at the end of the curve is parallel with the straight, so the transition is rather seamless. With an oval, that would not be the case.

[br]

Here are scaled representations of a several varieties of track layouts that range from the often used IAAF standard to the more original Drake Broken Back.

http://www.gillathletics.com/facilityCD ... acks-1.pdf

[Conor Dary]

Here are scaled representations of a several varieties of track layouts that range from the often used IAAF standard to the more original Drake Broken Back.

http://www.gillathletics.com/facilityCD ... acks-1.pdf

So Drake has a semi circle on one curve and a partial one on the other side. Interesting. At least you can run a 200 without problems.

[dj]

Here are scaled representations of a several varieties of track layouts that range from the often used IAAF standard to the more original Drake Broken Back.

http://www.gillathletics.com/facilityCD ... acks-1.pdf

So Drake has one normal curve and one non-constant curve. At least you can run a 200 without problems.

The Drake broken back was eliminated during the 2005 renovation of the facility.

[Conor Dary]

Actually there is such an international track now - Helsinki! When it was renovated in 2010 they put in a "broken back" design with 24 - 48 - 24 metre radiuses in the bends. The straightaways became 98.52 m.
This created an outcry from the athletes in the first major event held there, the prestigeous traditional match between Finland and Sweden that autumn. The strongest criticism came from Finnish 200 m runner Jonathan Åstrand, but even the female 400m runners at their 54ish pace had major problems with the changes in curvature.
However, it was argued by the people in charge that the design was not breaking any IAAF rules and that it would be too expensive to redesign the track to a standard configuration (also they would need to take some 4-5 metres from the stands in either end).

Thanks for the input. It confirms what seemed to me pretty obvious. It took me about 5 minutes of thinking about it that it would be a big problem for sprinters, but somehow the Helsinki folks never imagined it.

[Blues]

Actually there is such an international track now - Helsinki! When it was renovated in 2010 they put in a "broken back" design with 24 - 48 - 24 metre radiuses in the bends. The straightaways became 98.52 m.
This created an outcry from the athletes in the first major event held there, the prestigeous traditional match between Finland and Sweden that autumn. The strongest criticism came from Finnish 200 m runner Jonathan Åstrand, but even the female 400m runners at their 54ish pace had major problems with the changes in curvature.
However, it was argued by the people in charge that the design was not breaking any IAAF rules and that it would be too expensive to redesign the track to a standard configuration (also they would need to take some 4-5 metres from the stands in either end).
Then this year the arena hosted the European Championships and suddenly athletes (other than those from Finland and Sweden who already knew) from all over Europe were shocked to find themselves on a non-standard track design they never before had experienced. Probably not even as kids.
The consequences became immediately apparent with a flood of out-of-lane dq's in the first round of the men's 400m on the first day. In the first heat three out of seven were dq'd! And the simple reason was a track where you were forced to re-adjust your running not only going in and out of the bends but also twice within each bend.
The athletes (those not already dq'd ...) managed to accomodate for this as the competition went on - but of course it came at an expense performancewise. In the 200m it was obvious that no one dared to run all out on the bend. Instead they ran "carefully" to avoid any mis-stepping (or injury) and then tried to pour it on in the extralong finishing straight instead. But some athletes - like Ndure - immediately cancelled their 200m entries.
Now that everybody know about this Helsinki will need to overhaul this design of the track to ever have a chance to in the future host any major international event in their otherwise magnificent Olympic Stadium.

For anyone who isn't familiar with Helsinki.. Flying into the curve at normal speed on the one end of the track can definitely be tough.

http://www.time-to-run.com/europe/files ... ck.590.jpg

http://media2.roadkast.com/vincosport/H ... 0Track.jpg

[Randy Treadway]

Was it Helsinki or Oslo that floods their track in the winter time, to host elite level speed skating competitions?
I wouldn't think the speed skaters would take kindly to a double bend / broken back curve.

[26mi235]

From Lane 9 you start about 50 meters into the turn, which is into the shallow curve. You have to transition into the tighter turn for the last part of the turn, but for someone that can run 19.70, I do not think you would necessarily lose 0.30 seconds, about 3-4 meters because it is in the space of 30 or so meters of the track.

[dj]

Was it Helsinki or Oslo that floods their track in the winter time, to host elite level speed skating competitions?
I wouldn't think the speed skaters would take kindly to a double bend / broken back curve.

Oslo's Bislett Stadium.

[jla]

Was it Helsinki or Oslo that floods their track in the winter time, to host elite level speed skating competitions?
I wouldn't think the speed skaters would take kindly to a double bend / broken back curve.

Oslo's Bislett Stadium.

But it hasn't happened for some 25 years (since late 1980's).
Thereafter Bislett has never been used for speed skating.
Nor has any other major t&f arena.
Speed skating has moved indoors!

[gh]

and in any case, as far as I know they set up a speed skating oval by flooding the floor of the arena; it's not like they just iced-over the track!

[Wayne T. Armbrust]

I have calculated the striping for many tracks (http://www.computomarx.com/Jobs.htm), so this is my $0.02:

1. A track composed entirely of circular arcs and straight sections, with symmetrical curves 400m in circumference, will have staggers for races of any multiple of 200m which depend only on number of turns staggered and lane width. The staggers will be given by Li=nx(Ri-R1)xpi, where Li is the length of stagger in lane i, n is the number of turns staggered, Ri is the lane i measure line radius, R1 is the lane 1 measure line radius, and pi equals 3.14159. The measure line for lane 1 ls .3m from the curb if present, .2m from the inner lane line of all other lanes and lane 1 if no curb. This formula works for broken back tracks as well as simple curve tracks. For races that start in lanes and then cut in (or out as at Penn), the 800m and 4x400m, a break line correction has to be added to each stagger, which is different for each lane.

2. For broken back tracks of current design, an abrupt change of direction is not required (the old "flat spot" track at Drake an exeption), the tangents of the curves join smoothly, but you do have to make two changes of curvature in the curve. Of course, the same thing on a conventional track occurs entering or leaving a curve.

3. Broken back tracks of the type used in Helsinki (24 - 48 - 24 design) have such tight radii at the beginning and the ends of the turn that they are not suitable for sprinting at high level competitions. I always try to dissuade customers from installing a track of this type. Not just because of the tightness of the turns, but such a track is not necessary to enclose soccer fields. The IAAF Standard Track will enclose all but the largest soccer fields. Olympic Soccer is played on the infield of the Olympic Track which is of IAAF Standard dimensions.

4. Not all broken back tracks have the small radii at the ends and the large radii in the center. The old Jesse Owens track formerly in Ohio Stadium had the large radii on the ends and the small radius in the center. This link tells you all about broken back (compound curve) tracks. http://www.computomarx.com/Manual.htm#SEC8

5. The finish line should always be at the end of the straightaway, otherwise runners in races run in lanes all the way will not run the same distance on a curve. If the finish line is located 10m back from the end of the curve on a IAAF Standard track the runner in lane 1 in the 200 will run 84.390m on the straight and 115.610m on the curve. The runner in lane 2 will run 80.871m on the straight and 119.129m on the curve. In lanes four and higher, everyone will run 74.390m on the straight and 125.610m on the curve. The situation is even worse if the finish line is further from the end of the curve.

[deortman]

Given that the only sport that exceeds the statistics of baseball seems to be track and field, has anyone compiled the fastest times run in lanes 1-8 for M/W in the 100m, 110m/100mh, 200m, 400m, 400mh, and 4x100m relay? Follow-up question: Has a world record in any of the above events been set in lanes 1-2, or 7-8?
Perspiring minds want to know.

[gh]

hardcore fan named Jed Brickner used to maintain lane records (and as I recall SI thought it was so delightful they even gave him a pop for it).

As you'll see, it hasn't been touched since '03

http://users.rcn.com/bricklan/athletic/lanes/lanes.html

[br]

hardcore fan named Jed Brickner used to maintain lane records (and as I recall SI thought it was so delightful they even gave him a pop for it).

As you'll see, it hasn't been touched since '03

http://users.rcn.com/bricklan/athletic/lanes/lanes.html

http://www.lw.com/people/JedWBrickner

Jed W. Brickner is a partner in the New York office of Latham and Watkins, specializing in executive compensation and employee benefits law. Mr. Brickner is Chair of Latham & Watkins’ Finance Committee and has served on the firm’s Associates, Investment, Operations & Administration and Retirement Committees and has also served as Chair of the Employee Benefits Practice and Co-chair of the Tax Department in the New York office. He joined the firm directly from law school in 1980.

A frequent lecturer and writer on employee benefits topics, Mr. Brickner is a co-author of Collier Labor Law and the Bankruptcy Code and a member of the Employee Benefits Committee of the American Bar Association’s Tax Section. In addition, he has served on the Drug Appeals Board of USA Track and Field and been a correspondent for Track and Field News.