How long is the outside lane of a 400m track?

I stand corrected.

People who use d to represent the RADIUS of a circle aren't following convention. r for RADIUS, d for DIAMETER.

Just for all the people above who failed math at school, the circumference of a circle is C=pi*d, or as the diameter is twice the length of the radius C=2*pi*r

I liked the formula that had D = 400 + (400-2S)...

because it shows you the increase in distance that those extra lanes have.

if u measure the distance from each 400m start, they are 6m apart... therefore each lane is 6m longer than the inside lane, so if u run a full lap in lane 8, u would be running 400m + (6m x 8lanes) = 448m

if u measure the distance from each 400m start, they are 6m apart... therefore each lane is 6m longer than the inside lane, so if u run a full lap in lane 8, u would be running 400m + (6m x 8lanes) = 448m

All of you guys work with wrong numbers- except for the 10 lapper, who is correct. The width of each lane MUST BE AT LEAST 1.22m and at most 1.23m. That is a rule of IAAF. If it's narrower, it's not approved for competitions.

So, in that case, for each line (except for the 1st line) the lap around the track is circa 8m longer, give or take few cm. In eight lane, each lap is 456m long (7x8m=56m). I had measured it many times with measuring certified wheel, and-oh- I had participated in constructing 5 rubberized IAAF approved tracks in my country. So argue all you want, do mathematical reasonings, but come back and use the right numbers.

If I want to run in eight lane- for example for a tempo run, I know that 11 laps is 5000m and 22 laps is 100000m (altough it is 5016m at 456m/lap or 5005m at 455m/lap, but who cares- the good thing is that you don't have to run as many laps as in the first line)

trackhead wrote:

Ok, if I use 1.22m for the width I get 40.370995m for the new radius, and 253.65838m for the distance of both curves for a final distance of 453.65838m for a full lap in lane 8, or, when rounding to signficant figures, 453.66m using sig figs.

You only have three significant digits (1.22), which means your final answer is only accurate to the nearest meter (454 m, three sig figs), not the nearest hundredth meter (453.66 m, five sig figs).

The IAAF recognizes the fact that there are many tracks around the world with lane widths less then 1.22m (48 inches). Many tracks in the US have 1.07m (42 inch lanes). The IAAF Technical Committee added text during the last Congress to accept all tracks with lane widths up to 1.25m but all new tracks after 2004 shall have widths of 1.22 +/- 1 cm. A record set on a track with a lane width of less then 1.22m will be accepted because there is no advantage gained by running on a narrower lane.

The purpose of the requiring 1.22m for all new tracks is to standardize facilities around the world.

Regards,

David Katz

IAAF Technical Committee

PS I never heard of a "Certified Measuring Wheel" - but some manufacturers probably advertise it as certified.

A Measuring wheel is good for an approximate measurement butit has many potential problems:

People often run or jog with it reducing surface contact.

It's often difficult to measure the line (path) required.

For greater accuracy, it would need to be calibrated on the surface being measured- grass, dirt, etc.

Fartleker. wrote:

All of these calculations assume that the turns are perfect half-circles. Are they actually?

None of these calculations assume that. Read the full thread (specifically Simple Math's post).

Simple math wrote:

The track could be crooked, and meandering, or be a figure 8. It could have loop-the-loops in it, as long as the net result is that the track turns 360 degrees, the difference will be 2*PI*d.

I thought I was good at math but it's been many years since I was in school.

If the track is a figure 8 then aren't lane 1 and lane 8 the same length? And aren't all the lanes of equal length? Lane 1 starts out as the inside lane but then changes to be the outside lane once half of the distance of the track is covered. So everything evens out. Maybe I'm missing something.

On a more serious note, when measuring a track, I believe that lane 1 is measured so many centimeters or inches from the inside rail. Are the other lanes measures this same distance from the lane line or measured at the lane line?

calling malmo and jim fiore (again)

Tracks are measured in lane 1, 30 cm from the curb and 20 cm from the inside lane lines for lanes 2+. The lane line to the left is acutally part of the lane to the left. An athlete may step on the line to his/her right but not on the line to the left.

Indoor tracks can be measured in lane 1, 20 cm from the inside white line when there is no curb, and 20 cm from the inside lane for lanes 2+ (the same for outdoor tracks). Cones or flags must be placed on the inside line if there is no curb.

what's more important though is how long the second and third lanes are, because those are the ones most distance runners need to be concerned about running in.

You Can Never Know Enough Math wrote:

I thought I was good at math but it's been many years since I was in school.

If the track is a figure 8 then aren't lane 1 and lane 8 the same length? And aren't all the lanes of equal length? Lane 1 starts out as the inside lane but then changes to be the outside lane once half of the distance of the track is covered. So everything evens out. Maybe I'm missing something.

Good question. Note the stipulation "as long as the net result is that the track turns 360 degrees." Walk a figure 8 in the normal fashion, and you'll notice that your total turns to the right equaled your total turns to the left.

So for the figure 8 track, the runner would have to go around the outside of an 8, not actually crossing over. In general loops are okay, as long as they somehow add up to 360 degrees.

BTW, I thought that lane 1 was measured something like 30cm from the inside rail. Could be wrong though.

DUH. JUST MESSURE HOW LONG THE STAGGER OF THE 400 DASH IS IN LANE 8 AND MULTIPLYE THAT BY HOW MANY LAPS YOU RUN AND THAT IS HOW MUCH FURTHER IT IS.

nj12 has the easiest solution.

Go to your local track (gee, I sound like Larry Rawson)and using a tape measure, measure the distance from the common start/finish to the 400 meter start in the outer most lane. Then multiply that number by the number of laps. If you want to be more accurate- do the measurement 20 cm from the white lane separating the outside lane from the the lane to the left (otherwise the distance is approximately .628 meters per lap - quick calculation off of the top of my head)

Back on January 24, 2005 the #3 poster to this thread "HIYA" gave this answer. This thread could have ended there.

David Katz wrote:

nj12 has the easiest solution.

Go to your local track (gee, I sound like Larry Rawson)and using a tape measure, measure the distance from the common start/finish to the 400 meter start in the outer most lane. Then multiply that number by the number of laps. If you want to be more accurate- do the measurement 20 cm from the white lane separating the outside lane from the the lane to the left (otherwise the distance is approximately .628 meters per lap - quick calculation off of the top of my head)

This may sound trite -- I'm no mathematician here, but do these formulas include the lane line, that line between each lane?

Until now, I had always thought tracks were standardized, that only older ones had some funky attributes regarding curves and straights (we've a very odd one here at a high school in the western burbs of Chicago).

A. Trendl

A Runner's Dilemma

http://runnersdilemma.blogspot.com

Simple Math (engineering professor) implies that any shape (meandering straights,nonsmooth curves, loop-the-loops) will simplify to 2*PI*G as the incremental distance, where G is the difference between lanes. This holds true as long as a the finish ends up at the start line...

I did a quick test of this theory. Obviously a rectangle is one such shape, with non-smooth curves.

The original length is 2W+2L. The 8th lane is 2(W+2G + L+2G).

The difference is 8G. Not 2*PI*G.

So, it seems, maybe, Simple Math's simplification only works if the curves are partial but perfect circles? Which may be a reasonable assumption. However, some track curves may be more parabolic. And I'm *guessing* that would also invalidate the 2*PI*G theory.

Funny thread...I like the spirit.

I like experimental techniques so I used a google distance calculator site

http://www.daftlogic.com/projects-google-maps-distance-calculator.htm

and did the ratio of inside to outside lanes on two local tracks.

The answer I came up with was 448.8m

Also, using the "Wisdom of Crowds", I took the consensus of the estimates on this thread.

Average estimate 450.5m

Median estimate 450.0m

So, I'm pretty confident the answer is pretty darn close to 450 meters.