Smart phone to collect travel times

[John]

Hi Greg,

I just wanted to add a note (and thanks) for the recent change you made in a recent build. Importing travel time runs from an app on my Android phone works very well. The change to the Time/Date format has worked very well.

For everyone info, I've used "My Tracks" to track trips on my phone. It's a free app (you can search for it on Google). I'm sure the iPhone has a similiar app. I'm also sure there are others out there that work equally well.

The app can (and should) be set to record in a safe location. I do this in a parking lot while stopped. Then, start driving! When you are done, send the run to a CSV file (other formats are available, but the CSV maintains the speed info - Greg, please feel free to add any comments on the format). Out of fear of losing the data, I will stop at a safe location and email the CSV file to myself (again, many other ways to get transfer this, that's just the way I do it).

Back on the computer, I open the email with the CSV files and save them. In Tru-Traffic, I simply import these in the Trip Log page. With the new change to the Time/Date, I don't need to modify the CSV file prior to the import. Really slick!!!!

If anyone is interested, I could create a little PDF tech document of my process and post it here. I'd be interested in hearing of other experiences with collecting data with your phone.

BTW, I still prefer using my laptop and GPS. When doing signal timing, that is the only way to go. It give the instant QA/QC as you can see your position on the TSD. The phone is simply a means to open up additional data collection options.

Thanks,

John

[bullock]

Thank you for the tips, John.

Thanks also for sending (separately) the CSV file illustrating that there remained at least one commonly used date/time format that Tru-Traffic still wasn't supporting upon import. As you know, that's fixed now.

Regarding which file format to prefer when exporting from "My Tracks" for Tru-Traffic, users with Tru-Traffic ver. 10 and later should prefer the CSV (or TSV) format, as that includes the instantaneous speed measured by the GPS. Users with ver. 9.0 and prior may prefer the KML format, as it's more easily imported into the earlier versions of Tru-Traffic (which were rather inflexible), but the KML omits the GPS-measured speed, so if you're calculating fuel consumption and emissions using the trip logs, it's probably worth the extra effort to reformat a CSV file as needed to meet ver. 9.0's more picky expectations.

The GPS-measured speed tends to be smoother in time than the differential-calculated speed that Tru-Traffic substitutes upon importing files that omit the speed. The noise in the differential-calculated speeds is seen as artificial braking and accelerations when calculating fuel consumption and emissions using the "modal" models such as CMEM, giving exaggerated estimates of the fuel consumption, etc.

Regards.
Greg

[John]

Great, thanks Greg! The information on the export format is very useful.

John

[Chris]

Thanks for the app suggestion! I have been searching for something on an Android phone to use when I dont have my gps data logger or larptop. I am still looking for something on the iphone. "GPS Tracker" showed promise but have not used it enough to say its the way to go.

Chris

[Chris]

Just downloaded the ap and I am starting to use the csv file. I was wondering if someone can post the trutraffic v 10.0.15.2 import settings or post a screen shot of the window. I was also wondering if there was a way a user can define ans save the settings for their unit?

I have briefly reviewed the raw data and it look solid, however I have some hesitations in that I cant force the unit to gather a point every second. Any tips? I have tweaked some settings but I still have omissions when the unit is not moving. This is ok but I kinda like the warm fuzzies of not having omissions.

Has anybody compared this app's data to some known solid data? I guess some phones may have a better gps chip than others. I am going to compare an samsung S3 to my globalsat data logger.

[bullock]

If you can upload an example csv from the app, I'll be happy to show the appropriate Tru-Traffic import settings. I might even add it to the software's list of presets.

Tru-Traffic automatically saves the last-used import settings, so if you're frequently importing from the same device, you may not need to save them. Ver. 10 does not have an option for saving anything but the last used settings, or more than that one set of settings (although it has a number of factory installed presets that seem to automatically cover most of the csv files I've seen). Maybe a future version will let you save more settings with names that you may specify.

Tru-Traffic also discards redundant points when the unit is not moving -- it keeps only the first and last points marking the stop. If those are the only points the unit is skipping, then these won't affect Tru-Traffic as it would have skipped them anyway.

I'll be interested to hear what you learn comparing the Samsung S3 to the GlobalSat data logger.

Regards.
Greg

[Franklinf]

I've been using my Samsung S3 with an app called GPS Essentials and the accuracy is pretty good. Same as John, I have an option to record or "Track" my path and then export a .gpx file and import it into tru-traffic. Now, I did complete a few runs with my S3 and the GlobalSat data logger directly connected to a laptop via bluetooth at the same time, and they both matched up pretty well.
I compared these two with another gps unit and decided to stick with my smart phone and GlobalSat data logger.

Regards,
Franklin

[bullock]

Thank you for the report, Franklin.

Q1. Does GPS Essentials include the speed in the gpx file?

Q2. What version of GPX is the exported gpx file using, is it ver. 1.0 or 1.1? If you open the file in Notepad or Word, you should be able to read the version near the top.

GPX version 1.0 includes a specification for the speed, while the version 1.1 specification omits the speed (and the developers admit that this was an oversight).

If it turns out that GPS Essentials exports to GPX 1.1, or if otherwise it omits the speed, I'd recommend seeking an alternate format (CSV or TXV).

Regards.
Greg

[Franklinf]

Hi Greg,

Yes, I have the speed in the gpx file. It actually lets me export it as a gpx 1.0 and gpx 1.1.
I've been exporting with gpx 1.0 and everything seems to run smoothly.
Thanks for the heads up,

Franklin