I regularly travel the A53 in central England between Shrewsbury and Stoke
on Trent.
I have a TomTom GO 720

Going East, towards Stoke, it takes me along the A53 with a little bit of
A51 where the two 'mix and match' at Blackbrook

Heading west towards Shrewsbury, when I get into Baldwins Gate, it turns me
left, down a 'back lane' to join the A51 earlier, then, just before
Blackbrook, it takes me down a narrow country lane (Wharmadine Lane) then
back onto the A53 at Ashley.

Can anyone suggest why it goes the simple route one way, and then a stupid
route the other way?????


--
J B

J B wrote:
> I regularly travel the A53 in central England between Shrewsbury and
> Stoke on Trent.
> I have a TomTom GO 720
>
> Going East, towards Stoke, it takes me along the A53 with a little bit
> of A51 where the two 'mix and match' at Blackbrook
>
> Heading west towards Shrewsbury, when I get into Baldwins Gate, it turns
> me left, down a 'back lane' to join the A51 earlier, then, just before
> Blackbrook, it takes me down a narrow country lane (Wharmadine Lane)
> then back onto the A53 at Ashley.
>
> Can anyone suggest why it goes the simple route one way, and then a
> stupid route the other way?????
>
>
Depends on what your preferences are, but it may calculate just a few
yards/seconds difference in the routes. TomTom isn't very good at
considering the low speeds along back lanes

Peter wrote:
> J B wrote:
>> I regularly travel the A53 in central England between Shrewsbury and
>> Stoke on Trent.
>> I have a TomTom GO 720
>>
>> Going East, towards Stoke, it takes me along the A53 with a little bit
>> of A51 where the two 'mix and match' at Blackbrook
>>
>> Heading west towards Shrewsbury, when I get into Baldwins Gate, it
>> turns me left, down a 'back lane' to join the A51 earlier, then, just
>> before Blackbrook, it takes me down a narrow country lane (Wharmadine
>> Lane) then back onto the A53 at Ashley.
>>
>> Can anyone suggest why it goes the simple route one way, and then a
>> stupid route the other way?????
>>
>>
> Depends on what your preferences are, but it may calculate just a few
> yards/seconds difference in the routes. TomTom isn't very good at
> considering the low speeds along back lanes

It's just possible that it allows a different time for turning right and
turning left at a junction. Sometimes, it's going all the way round a
roundabout against the short bit between two adjacent roads. It then
takes the route that's quicker by a second or two or shorter by a few yards.

It's not just Tomtom that does this, all the others that I've tried do
it on occasion, too.

I'm still trying to work out though, why one particular program wanted
me to go from Biddulph to Whaley Bridge via the M6, M62, M60 and the A6,
when there's a route via A roads that's 36km as against 102km. I'd not
told it to avoid minor roads, either.

--
Tciao for now!

JOhn.

"John Williamson" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...

> It's just possible that it allows a different time for turning right and
> turning left at a junction. Sometimes, it's going all the way round a
> roundabout against the short bit between two adjacent roads. It then takes
> the route that's quicker by a second or two or shorter by a few yards.

So - I'll Google it

Shrewsbury to Stoke - on the A53
Turn right at Blackbrook onto A51 for 0.2 miles, then back onto A53
Only one right turn
Total (according to Google) 37.3 miles - 1hr 8 min

Stoke to Shrewsbury on Google says 38.4 miles - 1hr 8 min
Now if I alter the route to the one that tom-tom takes ...
39.5 miles - 1hr 12 min

?????


--
J B

J B wrote
> John Williamson <(E-Mail Removed)> wrote

>> It's just possible that it allows a different time for turning right
>> and turning left at a junction. Sometimes, it's going all the way
>> round a roundabout against the short bit between two adjacent roads.
>> It then takes the route that's quicker by a second or two or shorter
>> by a few yards.

> So - I'll Google it

> Shrewsbury to Stoke - on the A53
> Turn right at Blackbrook onto A51 for 0.2 miles, then back onto A53
> Only one right turn
> Total (according to Google) 37.3 miles - 1hr 8 min

> Stoke to Shrewsbury on Google says 38.4 miles - 1hr 8 min
> Now if I alter the route to the one that tom-tom takes ...
> 39.5 miles - 1hr 12 min

> ?????

The most recent tomtoms at least attempt to estimate real
transit times with traffic conditions included in that estimate.
It would be interesting to check whether the estimated time
varys with the one you believe is getting the route wrong.

"Rod Speed" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>
> The most recent tomtoms at least attempt to estimate real
> transit times with traffic conditions included in that estimate.
> It would be interesting to check whether the estimated time
> varys with the one you believe is getting the route wrong.

Sorry, can you expand on that please.

It's a 720, NOT a 720T


--
J B

JB

If you have a map and a navcore supporting IQ feature, Tomtom takes in
accounts the average speed on every road segment ,based on the actual date
and time you're going to travel (by 15min slots (!) in the latest maps
and/or navcore versions). No need for a TMC antenna for that.

Hope that helps.

Rgds.

Lionel


"J B" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> "Rod Speed" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>>
>> The most recent tomtoms at least attempt to estimate real
>> transit times with traffic conditions included in that estimate.
>> It would be interesting to check whether the estimated time
>> varys with the one you believe is getting the route wrong.
>
> Sorry, can you expand on that please.
>
> It's a 720, NOT a 720T
>
>
> --
> J B

J B wrote:
> "John Williamson" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>
>> It's just possible that it allows a different time for turning right
>> and turning left at a junction. Sometimes, it's going all the way
>> round a roundabout against the short bit between two adjacent roads.
>> It then takes the route that's quicker by a second or two or shorter
>> by a few yards.
>
> So - I'll Google it
>
> Shrewsbury to Stoke - on the A53
> Turn right at Blackbrook onto A51 for 0.2 miles, then back onto A53
> Only one right turn
> Total (according to Google) 37.3 miles - 1hr 8 min
>
> Stoke to Shrewsbury on Google says 38.4 miles - 1hr 8 min
> Now if I alter the route to the one that tom-tom takes ...
> 39.5 miles - 1hr 12 min
>
As others have said, different routing programs use different road
speeds and different algorithms, and not all use the same mapping data.
Even the two latest versions of Autoroute (2007 and 2010) give different
answers, but only by a tenth of a mile from Shrewsbury station to Stoke
station.

And *both* of them use the same different route (If you see what I
mean.) going the other way, which is just under a mile shorter.
(Quickest route selected in all cases.)

It can be annoying, though, and I find that often local knowledge will
give a route that beats all the computer systems.

--
Tciao for Now!

John.

J B wrote
> Rod Speed <(E-Mail Removed)> wrote

>> The most recent tomtoms at least attempt to estimate real
>> transit times with traffic conditions included in that estimate.
>> It would be interesting to check whether the estimated time
>> varys with the one you believe is getting the route wrong.

> Sorry, can you expand on that please.

> It's a 720, NOT a 720T

The most recent tomtom firmware, including yours, trys to calculate
the transit TIME, by including the speed that you are likely to see
moving over that route, by including data that it has on the actual
speeds achievable over segments of that route.

So, if the two possible routes are quite similar distances,
it may well decide that one is faster even if its a little
longer, and so offer that as the first route.

John Williamson wrote
> J B wrote
>> John Williamson <(E-Mail Removed)> wrote

>>> It's just possible that it allows a different time for turning right
>>> and turning left at a junction. Sometimes, it's going all the way
>>> round a roundabout against the short bit between two adjacent roads.
>>> It then takes the route that's quicker by a second or two or shorter
>>> by a few yards.

>> So - I'll Google it

>> Shrewsbury to Stoke - on the A53
>> Turn right at Blackbrook onto A51 for 0.2 miles, then back onto A53
>> Only one right turn
>> Total (according to Google) 37.3 miles - 1hr 8 min

>> Stoke to Shrewsbury on Google says 38.4 miles - 1hr 8 min
>> Now if I alter the route to the one that tom-tom takes ...
>> 39.5 miles - 1hr 12 min

> As others have said, different routing programs use different road
> speeds and different algorithms, and not all use the same mapping
> data. Even the two latest versions of Autoroute (2007 and 2010) give
> different answers, but only by a tenth of a mile from Shrewsbury
> station to Stoke station.

> And *both* of them use the same different route (If you see what I mean.) going the other way, which is just under a
> mile shorter. (Quickest route selected in all cases.)

> It can be annoying, though, and I find that often local knowledge will give a route that beats all the computer
> systems.

I wouldnt say its often, but its not that unusual.

It will be interesting to see whether the feedback from actual tomtoms
moving over routes, which is part of the feedback process with the
latest tomtoms, produces a reduction in that local knowledge effect.