MapMyRun giving measurers fits

The path measuring tools in mapmyrun (and Google Earth, and for that matter GPS) are accurate. The way people use them to measure courses is not accurate.

None of them is as accurate as a calibrated bicycle wheel for measuring courses, but they are accurate enough that, if used properly to measure the course, no one would complain about the difference they saw from the certified course distance.

Rather than saying mapmyrun is inaccurate, I think it would be better to explain how they used it incorrectly to measure the course.

I always use Google Earth to pre-measure so I have an idea on the length of the course. After measuring the course I know where the start and finish line are I will re do the measurement so that I can get an elevation chart for the race director. I will usually have 3.11 miles most of the time. Sometime I get 3.12 miles but not often. To get it that close you really have to pay attention to the bends in the road and you just have to be really careful in order to get the shortest route. There is no way you can take the corners on Google earth like you can when you are riding a bike.

I've never seen a discrepancy like that when using gmap-pedometer. (That's what I use and I've found it "friendlier" than MapMyRun but it may just be me). Usually really close.
Sometimes Google Earth is a lot better than gmap-pedometer, because you can go into historical images and pick one where the (deciduous) trees are leafless, giving a better view of just where that curb is that we're trying to hug.

I have the same experience as Bob and J.A. with Google Earth, though I use it only when I am faced with a course design that appears to be a "tight fit" with the available real estate. Going to the highest magnification and clicking as often as needed to replicate a calibration ride often proves to be close to the certified distance when I compare after the road measurement, as J.A. experiences. If you have used GE this way, you know that this is a tedious procedure, and even this level of exactitude does not approach a certification ride for accuracy, as J.A. states.

GMaps does a good job of estimating where you have some real estate to work with, in my experience. I use a combination of the "For Runners" and "Straight Line" measurement tools in GMaps to get a facsimile of the course to be measured. The more turns in the course, the less accurate I find GMaps (or any on line tool) to be - overstating the course distance, naturally. My brief trial using MapMyRun was so unsatisfactory that I stopped using it years ago.

Mark, I have not tried MapMyRun in the last couple of years, but like most of us, I suspect, I sometimes get a MMR of the course I am asked to measure. Based on my experience with MMR, I have no difficulty saying "MMR is not accurate enough to display your course on your race web site" or something like that. I think to say otherwise could be misinterpreted to imply that RDs can just use MMR and forget about certification. While I suppose you or I or any of us reading this could create a MMR that might be close, I suspect we all agree MMR will never supplant certification measurements.

Some MMR courses I get turn out to be laughably short. I do not know how others of us do this, but I always take the MMR, pencil drawing, turn-by-turns or whatever I am given by my client, and then create a GMap of the course, showing what I believe will achieve the certified distance. I send it to the client for confirmation. Sometimes the client is surprised at the amount of distance that is likely to be added to their course.

Mark, you educated me on the fact some or most new GPS watches are accurate, and that much more of the error in course measurement by GPS device-wearing runners is typically due the lack of tangent running than GPS inaccuracy. However, I break with you about educating anyone about how to use MMR. I see no value in showing anyone how to use MMR or any on line tool for course measurement. Maybe you have had a different experience with MMR. For me, it is good enough that they can just rough out the desired path so I get the gist. I agree with the state certifier Pete talked to who stated that "...MMR is good enough (only) for training runs and course layout".

I just hate the G.D. ad boxes that keep floating into the way!

Jim, you may want to try the free download AdBlock to your browser. I use it in Firefox and I never have any ads.

I use America's Running Routes (http://www.usatf.org/routes/) Satellite view to check a course before going out to measure. The map view doesn't always show the exact path of roads. If you switch between map and satellite, the discrepancies are quite obvious.

Because of the annoying advertisements, I always suggest America's Running Routes over MapMyRun when race organizers inquire about course certification.

I am going to defend MMR. I use it for every course I measure. I feel it is simple to use, and $30 per year is a small price to pay to get rid of the ads. Many of you spend much more on that for postage, envelopes, and paper to mail applications and certs to the next level.

That said, proper use of MMR allows for very useful measurements. I overcome the tediousness of trying to follow curbs exactly by allowing for some cutting of corners when I map. This is similar to our SCPF, in that my endpoints come out within about 20 feet of what I map.

I do have most race directors map their course first, then send me a link. I look at it, and normally have to tell them, again, they should have turned off "Follow Roads". It is easy for me to re-map it. A 5k may take 2 or 3 minutes to map, and a marathon can be mapped in 5 minutes, or less.

I can then export the route as a GPX file, and put that onto my Garmin Oregon. I follow it while measuring, which is much easier and faster than constantly checking a map. I don't know if the other programs allow you to export a useful file.

To me, MMR is a great tool. If used properly, it is accurate enough to plan a course very well. If it is not used properly, it results in a very inaccurate length of any course. Likely no different than any other mapping tool.

Keep in mind, also, that every mapping tool that uses satellite imagery will be inaccurate, due to "rubber-sheeting" of the imagery. Since the images are not exactly rectangular in each photo, sides/corners are distorted a bit to make imagery match. If you look closely, you can see this at the corner of many tiles. I got this from the satellite imagery company itself.

Mapping tools, like any other tool, are only as good as the user.

The export feature sounds cool, but if you don't have a Garmin, MMR is no better than GMap or America's Running Routes, IMO.

Well, we can use the tools available to us to make our job more efficient, or we can ignore progress.

Since I measure so many courses each year, and the purchase is a deductible expense for the "business", it makes sense to use a Garmin (Oregon 450, in my case). Plus, as I am driving to the course, I can see where I am going to, so I don't over-shoot, or get lost. I'm heading to Colorado Springs Saturday morning, about 4:30, so having the course and splits already on the Garmin will allow me to get there, without trying to see street signs in the dark. Multiple reasons, in my book, for investing in a tool that makes the process more efficient. And people call me a tightwad, Jim!

Just had the same experience with a runner claiming a 5km course was 3.32 miles long when he used Map My Run to check the length. It took several emails to convince him that the course was indeed 5km.

The export and import features are important for more than just your Garmin.
If you choose to use a mapping app that doesn't have an export feature, then you'd better like it, because you're stuck with that app for the rest of your days. No way to move your maps anywhere else.
An import feature is nice so you can read in maps that the RD sends you from another app. Without an import feature you either have to recreate his route or work in his app.