RANT: TomTom routing doesn't use speed limits!

[bednorem]

"The secret to a happy life is low expectations" - Multiple sources.

Allow me to vent. I'm a 15 year veteran of GPS use, and I've been using various automobile nav solutions for about 10 years now ( started off on laptops!). There have always been 3 major sources of bad "fastest" routes: poor algorithms, bad maps, and bad speed limit estimates. Garmin has always had the edge on all 3, but still far from perfect. Well, here in Texas, just about every routing device does poorly on long-distance trips, because they always want to use Interstate highways. Why is this bad, you ask? Because the majority of Texas state highways, including farm-to-market roads, are 65-70 mph. Unfortunately, almost all navigation programs use default speeds for each "class" of roadway, and these are usually in the 40-50 mph range. As a result, routing and ETA's are horribly inaccurate. So back in 2002, when I discovered that my Garmin MapSource software (which came with my Garmin GPS V; my favorite all-around GPS of all time) allowed me to actually edit these default speeds, I was ecstatic! Suddenly, I could use values that were appropriate for a given region, and lo and behold, I had superb back road routing on my laptop!!! Angelic choirs were heard in the heavens! This concept, with its breathtakingly elegant combination of power and simplicity, was so obviously needed in every navigation device that only the most brain-dead of developers would not include it in their feature set. I waited for it to sweep through the industry. And waited. And waited.

Meanwhile, map system improvements continued to converge, and everyones algorithms got better and better. I took the plunge and bought TomTom navigator 5 for my Treo. I loved the interface, but the aforementioned problem continued to drive me nuts.

Then, to my great delight, TomTom releases MapShare 2.0, which allows me to edit speed limits!!! "AT LAST!", I say to myself, "Navigation Nirvana has come within my economic grasp". I shop furiously, and find a deal on a TomTom 130s. It works fabulously in the city (Houston), and I could hardly wait to sample its delights on a cross-country trip to Lubbock (about 500 miles Northwest). While my son drove, I laboriously edited speed limits along my favorite route. (In case you didn't know, most highways are divided into multiple segments in the TomTom maps, and this one averaged about 1 segment every 3 miles. 500 mile trip. Do the math.) I then asked it for a "fastest" route. It told me to take the Interstate. "No, no", I said to the TomTom. "You misunderstood. Let me re-enter some of the speed limits and make sure you get this right." I tried a shorter, 25-mile destination. It sent me in a large 40 mile loop around to my destination. Hope fading, I experimented some more. To my dismay, I found that the routing calculations ignored my carefully entered speed limits. And to make it worse, I determined that TomTom thought that rural Texans were incapable of driving over 40 mph. Deep, deep despair.

"Ah, well", I sighed. I'll have to go with the disappointingly primitive Garmin Nuvi interface. I begin to research MapSource and the Nuvis on-line. To my horror and disbelief, I find that this feature does not exist on the Nuvi, or on ANY of Garmin's car navigation devices. Oh, to be sure, the editing capability exists still in MapSource, but it cannot be passed to the Nuvi!!!

OK, ALL YOU PRODUCT DEVELOPMENT GURUS. I CAN GET THE FACT THAT YOU DON'T WANT THE VAST NUMBERS OF CLUELESS NON-TECHIE BUYERS TO ACCIDENTALLY SCREW WITH THESE NUMBERS. BUT IT WOULD BE TRIVIAL TO LET US CHOOSE THIS IN A DEEPLY-BURIED OPTION MENU AND PASS IT TO THE UNIT!!!! OR AT LEAST MAKE IT DIFFERENT FROM STATE-TO-STATE. PLEEEEASE?????

And now I look with longing eyes at the IQ Routing in the (much more expensive) 930. But can I risk it? Dare I raise my hopes again? Fork over more of my hard-earned money, only to have my expectations unmet? Would it even care about Texas back roads, which are hardly ever travelled by the sophisticated urban navigators? Perhaps in time, but for now I'll nurse my disappointment.

"The secret to a happy life is low expectations" - Multiple sources.

 

[Michael Quinlan]

I'm sure most of us can understand your frustration. IQ Routing does work well, but only where the data is available. I'm sure if you post a few routes with start and end locations, some of us with IQ Routing would happily test them on our devices and post the results, letting you make your own judgement.

Alternatively, if there's a retail store nearby, or that you pass in your travels, you can try them there as well.

As a test, I entered a route from city center of Houston, TX to the city center of Lubbock, TX. My TT warns me that:

The fastest route is now being planned for you. However, please note that in TX there is not enough traffic history available to optimise this route using 'IQ Routes'

I got this same warning for NJ the first time I tried to use it, but it does work well for me in most areas.

Anyway, the route it came up with for a weekday is 8:53 hours, and 580 miles, and goes like this:

• Start: Houston TX
• 0.55 Miles; Turn Right; Wood St
• 0.60 Miles; Turn Right; Girard St
• 0.75 Miles; Turn Right; I-45 NB
• 229 Miles; Exit Right; 276A Ft Worth
• 259 Miles; Keep Left; I-20 WB
• 269 Miles; Keep Left; I-20 WB I-820 Abilene
• 274 Miles; I-20 WB Abilene
• 416 Miles; Keep Left; I-20 WB
• 419 Miles; Keep Right; I-20 WB El Paso
• 464 Miles; Exit Right; 238A Snyder
• 580 Miles; End; Lubbock TX

I hope this helps answer your question.

 

[21rouge]

I'm sure most of us can understand your frustration. IQ Routing does work well, but only where the data is available.

As a test, I entered a route from city center of Houston, TX to the city center of Lubbock, TX. My TT warns me that:
I got this same warning for NJ the first time I tried to use it, but it does work well for me in most areas.

The fastest route is now being planned for you. However, please note that in TX there is not enough traffic history available to optimise this route using 'IQ Routes'

Interesting Michael as I have never seen that warning . I was thinking that in Canada, IQ just like ALG, wasnt yet implemented but given that I have never seen such a prompt for any route my 730 has generated I wonder .

Have others seen such a warning for their x30 unit when using IQ routing?

 

[dhn]

Just to be sure........apparently the ALG (meaning the multiple arrows on the status bar) will NOT appear if your preference is for a vertical status bar; they only show when the bar is horizontal on the bottom of your screen.

 

[Old Baldy]

I can't agree with the idea that TT does not use the speed limit data in the latest >= v7.20 maps, which contain the speed limit data from TeleAtlas.

I find that my old TT1 V2 is extremely accurate with regards long distance ETA calculations....often with me arriving within MINUTES of a 9-11 hour drive!

This was born out repeatedly, on various road trips from Michigan to Halifax, from Michigan to Florida, and also on my recent motorcycle trip to Alaska/Arctic Circle (9000 miles in 3 weeks), when the TT was extremely accurate in all ETA calculations for many hours of driving/riding distances, along roads of varying speed limits.

I find that while my wife's new Garmin Streetpilot C580 (a good quality, old style unit that can now be had for $190!) - is superior in nearly every way to my TT1, it is LESS accurate in terms of ETA accuracy, as it is almost always OPTIMISTIC in ETA, and then ends up incrementally pushing out the ETA arrival time over the course of the trip. I wish the Garmin had the ETA /algorithm accuracy of the little cheapie TT.

I can only conclude that the TT actually does use the speed limit data from its maps, for this level of accuracy, or, if not, is incredibly clever in estimating the road speeds.

I do agree 100% that all units should utilize the actual road speed limit data for their routing and ETA calculations, and even further, should allow the user to apply a percentage or nominal over/under speed limit adjustment to mimic their own personal preference in speeding, and also apply specific rest period frequency and duration assumptions for the trips with some level of logic (e.g. why on earth would a unit assume you are going to stop for a 30 minute rest break 10 minutes from your final destination?)

 

[Michael Quinlan]

Just to be sure........apparently the ALG (meaning the multiple arrows on the status bar) will NOT appear if your preference is for a vertical status bar; they only show when the bar is horizontal on the bottom of your screen.

My preference was for a vertical status bar because of the better (IMO) aspect ratio of the map that went along with it. I was disappointed when I discovered that ALG only worked with a horizontal status bar.

 

[Bama Rambler]

I, like you, have spend many minutes entering speed limit data where ever I've gone only to find out that it makes no difference in routing. I also have a personal gripe about the speed limits that subtract one from the number entered (i.e. 45 shows as 44).

 

[bednorem]

Quote: Anyway, the route it came up with for a weekday is 8:53 hours, and 580 miles, and goes like this:
Start: Houston TX
0.55 Miles; Turn Right; Wood St
0.60 Miles; Turn Right; Girard St
0.75 Miles; Turn Right; I-45 NB
229 Miles; Exit Right; 276A Ft Worth
259 Miles; Keep Left; I-20 WB
269 Miles; Keep Left; I-20 WB I-820 Abilene
274 Miles; I-20 WB Abilene
416 Miles; Keep Left; I-20 WB
419 Miles; Keep Right; I-20 WB El Paso
464 Miles; Exit Right; 238A Snyder
580 Miles; End; Lubbock TX

I hope this helps answer your question.

Yep, that's the "Interstate" route. But the fastest route (by far) is 290 to Brenham, and then state highway 36 to Abilene, and then the interstate to lubbock. If you drive the speed limits, this route is almost 1 hour faster. (I won't reveal my actual speeds.)

I also have noticed that the Teleatlas maps have gotten much better at eta's and I draw the same conclusion that they MUST be using some road-specific speed limits. I really like that idea of applying a "correction" factor to a given route/path.

 

[eldorado]

I guess I'll just stick my nose in here and ask, what is so important about the speed limit.. I just plug in my route and go, look at the ETA and see how close I get upon arrival, I drive mostly the speed limit and also notice that it constantly updates ETA as I go, I always leave with plenty of time so arrival is secondary, I just tell everyone I'll be there by............time and I make it, unless you/I run into construction or accidents, I also look up the route on Google so that will always tell me approx. times. Worrying gets me wound up so I don't worry, by the way I use a TT one xl so don't have all the trick stuff some of you have, I like gadgets of course but can't handle the "2" complicated techie stuff........

 

[GeorgeII]

Using Tyre I visually route myself the best route possible --- "shortest distance between two points is a straight line."

My recent trip (248 miles) from my home in Pensacola Florida to a destination in Jackson Mississippi was a clean and uncluttered routing and I arrived within 5 minutes of my displayed ETA.

I have a TT one XL-s and with the help of Tyre I have full confidense in its ability.

I will say that without Tyre I would make the first person who wanted my TT a gift of it. I think the software in it simply stinks. Any good and well led software group easily could produce a much better GPS.

Take these GPS units with a grain of salt ----- I am of the opinion that they will eventually get you where you are going even if they do a sloppy job of it.

 

[Old Baldy]

I guess I'll just stick my nose in here and ask, what is so important about the speed limit.. I just plug in my route and go, look at the ETA and see how close I get upon arrival, I drive mostly the speed limit and also notice that it constantly updates ETA as I go, I always leave with plenty of time so arrival is secondary, I just tell everyone I'll be there by............time and I make it, unless you/I run into construction or accidents, I also look up the route on Google so that will always tell me approx. times. Worrying gets me wound up so I don't worry, by the way I use a TT one xl so don't have all the trick stuff some of you have, I like gadgets of course but can't handle the "2" complicated techie stuff........

Well, sometimes you may want to simply get somewhere in the quickest time, and not spend an extra hour or two on the road, especially on a longer trip.....wouldn't you?

If the GPS used the real speed limits, it could find the quickest route. Without the speed limits, or using invalid limits, it cannot find the best (quickest) route amongst a number of alternatives with different speed limits on the actual roads.

 

[Michael Quinlan]

I just read another thread where the OP claimed that adjusting the speed limit downward resulted in different routing. However in this thread, the OP adjusted speed limits upward and saw no routing changes. Perhaps TT uses the road-class-specific speed for route calculations, but uses the speed limit as a "cap" when it is lower than the road-class-specific speed?

Anyway, a suggestion to the OP: try adjusting the speed limits on the roads you want to avoid downward, and see it that gets the results you're looking for. I realize this won't help with the ETA problem, but it might influence the routing.

 

[gerryc]

just a thought.. if 'Garmin always has the edge' on this. Suppose I get a garmin, what will be the rant i'll be giving the garmin guys' to make it perform like the Tomtom?

I mean what is it that tomtom has that's preventing us from owning a Garmin instead?

 

[bednorem]

I just read another thread where the OP claimed that adjusting the speed limit downward resulted in different routing. However in this thread, the OP adjusted speed limits upward and saw no routing changes. Perhaps TT uses the road-class-specific speed for route calculations, but uses the speed limit as a "cap" when it is lower than the road-class-specific speed?

Anyway, a suggestion to the OP: try adjusting the speed limits on the roads you want to avoid downward, and see it that gets the results you're looking for. I realize this won't help with the ETA problem, but it might influence the routing.

Good suggestion to check the downward correction on the other route! It was urban surface streets in Houston, which may be handled differently. I'll give that a try. I'm also going to do some more rigorous testing using my daily drive to work. I'll keep y'all posted.

just a thought.. if 'Garmin always has the edge' on this. Suppose I get a garmin, what will be the rant i'll be giving the garmin guys' to make it perform like the Tomtom?

I mean what is it that tomtom has that's preventing us from owning a Garmin instead?

Sorry if it sounded like I was putting Garmin ahead of TomTom. I was just giving some history on the feature. Back in the day, Garmin was the industry leader in navigation algorithms, and the NavTeq maps were more accurate than any of the others for the U.S. Times have changed, which is why I was careful to say "has always HAD the edge."; past tense. TomTom has caught up, as has TeleAtlas. As for Garmin, the ability to mod these speeds and download the GPS unit disappeared several years ago; It's been pulled from everything except the PC version of MapSource; which can't even be used for live navigation; just trip planning. If you hit the Garmin forums, you'll find a lot of long-time users that are ticked off about this.

My rant is with ALL of the consumer-oriented GPS car nav units (including Garmin's Nuvi line) for not giving the user a way to work around this. My specific frustration with my 150 is that it comes so close! It gave me the long-awaited speed editing feature and then I found out it didn't use the speeds I edited. Like I quoted, it was the expectation that led to the disappointment. But hey, I don't want to make it sound like my little 10-year tiff over this feature with the GPS industry keeps me from loving my fantastic little 150-S!! Compared to the map gripes from Canada, a little ETA error on Texas farm-to-market roads ain't that big a deal.

 

[21rouge]

Compared to the map gripes from Canada, a little ETA error on Texas farm-to-market roads ain't that big a deal.

Thanks for thinking of us .

 

[Buddharay]

i'd also ask you to consider that many of these new technologies are cutting edge, and are constantly evolving as we use them. most computer programs aren't perfect when they initially launch; it takes some updates, some patches, some consumer feedback to make things work better overall. so, yes, i'm sure there are some limitations right now - however, i'd advise you to show some patience. what tomtom and tele atlas are doing right now is literally uncharted territory. seeing what open source projects on the internet makes me optimistic for the success of mapshare and iq routing and all the other tomtom features that can have user-generated information; overall, i think it makes a more complete product. o ye of little faith, there is hope for us yet. stick with your tomtom.

 

[bednorem]

I just read another thread where the OP claimed that adjusting the speed limit downward resulted in different routing. However in this thread, the OP adjusted speed limits upward and saw no routing changes. Perhaps TT uses the road-class-specific speed for route calculations, but uses the speed limit as a "cap" when it is lower than the road-class-specific speed?

Anyway, a suggestion to the OP: try adjusting the speed limits on the roads you want to avoid downward, and see it that gets the results you're looking for. I realize this won't help with the ETA problem, but it might influence the routing.

AHA! TomTom DOES use the edited speeds, but only if you lower them! I experimented with 3 destinations and several routes. Here's what happened:
** if you REDUCE the speed limit, then the routing uses the reduced speed!!! (you deduced correctly, Mr Quinlan.)
** If you INCREASE the speed limit, then the routing ignores it and uses the standard speed.
** If you INCREASE the speed limit along the calculated route, the ETA calculation ignores the increased speed.

In short, you can decrease speed limits to discourage routing for certain roads, but you cannot increase (or "correct") speed limits to encourage a route or correct an ETA. This fits with the experiences in another recent post about routing through "back alleys"

So the verdict is that the routing DOES use the edited speed limits on a street-by-street basis (yay!) but only if they are decreased (boo!).

I'm scratching my head as to why they wouldn't use the ones that are increased. It has to be that they're protecting themselves from something. Hmmm. If a user accidentally makes a speed limit too slow, then all that happens is that the routing finds a less optimal route, but that route still gets you there and has the typical ETA accuracy (i.e., conservative). SoTomTom lives up to the user's (low) expectations. But if the user accidentally makes a speed limit too fast and the routing uses it, then he would get a route and an ETA that's too optimistic. He/she gets there late, and TomTom has an irate customer.

Hey TomTom, put the option in the preferences!! (Any of you unix gurus want to try to hack this one? I'd pay!)

 

[Old Baldy]

just a thought.. if 'Garmin always has the edge' on this. Suppose I get a garmin, what will be the rant i'll be giving the garmin guys' to make it perform like the Tomtom?

I mean what is it that tomtom has that's preventing us from owning a Garmin instead?

Many of us probably do use both. I've been using various GPS systems (currently have 5, of which two are Garmin and 1 is TT), for many, many years now.

NONE of them is perfect. Most of them have some nice features and some not so good "features".

From my own experience, the following generalizations exist between the TT and the Garmin.

User Interface customizations - TT wins with much more configurability.

Useful screen info - a tie. I like the Garmin's top status line which CLEARLY tells you the road you're on, and your next exit and road. Very nice. On the othe rhand, I miss the lack of remaining mileage, speed limits and speed displays that the TT provides, and, especially, the next turn direction arrow.

Guidance instructions - Garmin, but only because it tells you which side of the road your destination is on, which is really nice. TT1 does not.

Screen detail - Garmin allows the zoom level to stick. TT1 does not. I HATE the fact that the TT returns to a default zoom level, that is too "zoomed" for my preference. I prefer a higher, less detailed view of a broader area.

POI - Garmin, as I always seem to find what I'm looking for, quicker. The TT often does contain the data, but the actual search is less intuitive and more complex (more screen taps/entry required)

Looks, form factor - TT. The old StreetPilots are real clunky.

Guidance/routing - Garmin. From side-by-side comparisons, the garmins seem to find the more "logical" routes for me, when in "fastest" mode

ETA calculation - TT. The garmin is overly optimisitic in ETA, and almost always pushes the time out, even when traveling above the speed limit. This is bad, because if you're told someone you should be there by xx:xx, you often don;t make it. The TT is very accurate over long routes.

Maps - Close. Perhaps the Garmin is a little more accurate with latest streets in my area, but the TT is also quite good. The TT seems to show more detail, with the larger, more detailed regional maps. I'm running the latest maps in both the garmin and TT.

Trips/planning - TT wins easily, with multiple via/destination itineraries, which neither of my Garmins have. Although, to be fair, I seldom actually USE this feature when navigating, even on my recent 9000 mile motorcyle trip to Arctic Circle and back.

Traffic - TT. The TT's cell-based traffic update works well, and does not require any extra hardware, which is needed on the old StreetPilots (and it's not cheap!).

Multimedia and other features - Garmin wins, because the C580 has BT handsfree and phonebook functionaility, which the TT1 does not have. I will never use the Garmin's MP3 and MSN content for gas prices, movie times, etc and will not be extending the free MSN-Direct subscription for the garmin.

EDIT: I forgot to add about the mount hardware. For me, the Garmin wins, with a better suction mount that simply does not fall off the damned windscreen like my TT always does, sooner or later. BUT, the fantastic old C330 mount is vastly better than the poor newer C580 mount, which is so sloppy-loose in the ball connection to the unit, that when I travel on dirt roads, the C580 droops down to point at the floor within a few miles! This is only fractionally better than the TT1 mount which falls onto the floor! The C330 is like a rock, and does not budge!

Overall conclusion - I think the Garmin is functionally slightly superior in the basic, key areas of map, routing algorithms and screen turn instructions and destination voice instructions, BUT....

...I still like my TT for its more configurable user interface, and the web Tire planning interface.

That's my take on the 2 makes....from a very simplistic comparison of 3 specific models, which realistically had the odds tilted in the favor of the garmin, because the C580 was the previous top-of-the-range automotive car GPS from Garmin, while the little over-achieving TT One was the bottom of the TT range. Take this FWIW......

 

[gerryc]

thanks.. great info on the gps units.

just to add that on on my tt 930, there is a way to disable autozoom.

 

[Buddharay]

Guidance instructions - Garmin, but only because it tells you which side of the road your destination is on, which is really nice. TT1 does not.

Guidance/routing - Garmin. From side-by-side comparisons, the garmins seem to find the more "logical" routes for me, when in "fastest" mode

shouldn't advanced lane guidance and iq routes at some point remedy these problems? tomtom is making steps to improve these things... what is garmin doing to improve their products?

Maps - Close. Perhaps the Garmin is a little more accurate with latest streets in my area, but the TT is also quite good. The TT seems to show more detail, with the larger, more detailed regional maps. I'm running the latest maps in both the garmin and TT.

tele atlas's partnership with google and tomtom i think will eventually result in tomtom's having the most accurate maps. another factor that tomtom will be improving in the future.

EDIT: I forgot to add about the mount hardware. For me, the Garmin wins, with a better suction mount that simply does not fall off the damned windscreen like my TT always does, sooner or later. This is only fractionally better than the TT1 mount which falls onto the floor! The C330 is like a rock, and does not budge!

the easyport mounts on the 130S and 330S hold pretty darn well. i imagine that's going to be a technology that's going to be expanded to all the devices at some point.

i love my tomtom, honestly, because i think they're the GPS provider of the future. they're constantly making progress with their technologies (mapshare, iq routes, advanced lane guidance, easyport, tele atlas deal, etc.. all in the past year). soon, i'm not sure the competition will be close. that's just my opinion.