Alternative Route/Road Block

Petekk · Regular Visitor Joined: Mar 06, 2004 Posts: 137

Having used TT2 for a few weeks, I am confused.

I calculate a route (using strict) and start to travel along it. What are the differences in then calculating an alternative route? or telling TT2 avoid a specific road?

How do others use these functions?

lbendlin · Posted: Sat Mar 06, 2004 5:22 pm Post subject:

Now you got us confused, too. What exactly is your problem?
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Privateer · Posted: Sat Mar 06, 2004 6:36 pm Post subject:

"Strict" calculation can take a long time, especially on long distances. This option exhaustively checks every little alley in case it provides a short cut that will reduce your trip by some extra seconds or meters. I tend to use “normal” calculation

I don’t know what TTNav will suggest as an “alternative” route because when you are using strict calculation you have instructed TTNav that you want the optimum route – anything else isn’t. Wink

The avoid road is useful if you have forewarning (e.g. from Trafficmaster, etc) of a delay or traffic jam on a certain road that you know TTNav will direct you to use. You can use that to recalculate another optimum route only this time without the affected road. However if you’re already on the road and the delay is between you and the next junction/exit then TTNav won’t be able to help you.

Regards,
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Robert.
iPhone 6s Plus, iOS 14.0.1: iOS CamerAlert v2.0.7
TomTom GO Mobile iOS 2.3.1; TomTom (UK & ROI and Europe) iOS apps v1.29
Garmin Camper 770 LMT-D

Petekk · Regular Visitor Joined: Mar 06, 2004 Posts: 137

The options for road block, or avoid a specific road are self explanatory, but what is the benefit of the "alternative route" option? When.Why would people use it?

Privateer · Posted: Mon Mar 08, 2004 12:34 pm Post subject:

I suggest that you perform a test using "Strict" calculation. Plan a route from A to B and make a note of the estimated distant and time of the route and then repeat the test using “normal” calculation for the same route. Certainly when using normal calculation, I found that it did give an alternate route. Thumbs Up

If you don’t like the first route, then the “Alternate Route” option will do what it says on the tin and try to give you a different route. Wink

Regards,
_________________
Robert.
iPhone 6s Plus, iOS 14.0.1: iOS CamerAlert v2.0.7
TomTom GO Mobile iOS 2.3.1; TomTom (UK & ROI and Europe) iOS apps v1.29
Garmin Camper 770 LMT-D

woody67 · Occasional Visitor Joined: Feb 03, 2004 Posts: 34

For example, I live relatively close to two motorways, and some major A roads.

TT will always try and send me onto these as part of my journey. I know that this may not always be the best way to go, so I ask for an alternative. By the 2nd or 3rd try, I get a better route.

The other way to try and force a particular route, is to set the speed preferences to favour certain types of road.

NickE · Posted: Tue Mar 09, 2004 12:08 pm Post subject:

Just had an interesting one - planning a route from Bedford to Stansted. First route it gave (all options are defaults) takes me towards Cambridge then pick up the M11. About 55 miles, time is 1:09:10. Draw an Avoid Area over Cambridge, since I usually prefer A1-A507 for this run. It recalculates and comes up with my preferred route, shows 44.5 miles and now only 1:08:55. I realise that the time is only fractionally shorter, but I still would have expected this to be the first choice as it is quicker than the first one it gave me. Confused

lbendlin · Posted: Tue Mar 09, 2004 3:15 pm Post subject:

Did you have strict calculation enabled? TomTom may have stopped short of the optimal route because in normal mode it has a time/quality tradeoff - it stops calculating after a certain time.
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NickE · Posted: Tue Mar 09, 2004 3:23 pm Post subject:

No, it was all on standard settings - I'll try again on strict and see what that comes up with.

NickE · Posted: Tue Mar 09, 2004 3:31 pm Post subject:

No, still the same result - also get 'my route' if I ask it for an alternative without the Avoid; the alternative choice is 10 miles shorter and 20 seconds faster and yet TTN2 doesn't present it as first option.
Can there be some other bias in the algorithm affecting it e.g. number of right turns, roundabouts etc.? Not that any of this matters very much, but once you start thinking about it, it's hard to stop!

lbendlin · Posted: Tue Mar 09, 2004 3:53 pm Post subject:

oh dear, another fine man lost in the voids of the street routing maze...
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woody67 · Occasional Visitor Joined: Feb 03, 2004 Posts: 34

shammy · Occasional Visitor Joined: Dec 10, 2003 Posts: 19

Wouldnt it be good to be able to store your preferences re *areas to avoid* as well as saving routes for repeat use? Another item for the wishlist.

Tom got me out of trouble today - heard traffic news warning of a major holdup on the A38 in Derbyshire, told him to take me elsewhere and lo and behold I headed off into the hills. Arrived at my destination just a few minutes late, but much earlier than if I'd stayed on the original route.

Good old Tom.

clem · Posted: Thu Mar 11, 2004 7:55 pm Post subject:

Yeh, the avoid road block feature is what for me, makes TTNAV2 stand out above the other routing programs.

Thing is though, it could be soooo much better. I spend loads of time on the motorways and RDS traffic alerts are always given by junctions e.g. M62 tailbacks due to an accident from junction 22 - 20. How cool would it be if you could just tap avoid roadblock, TTNAV detects your on a motorway so it presents an extra avoid option like 'Motorway Junctions', then it presents a number of junctions to avoid starting with the next one. Bingo!

At the moment you have to set a new destination (in the example this would be Junction 20 on the M62 - which isn't easy cos you need to know the city this junction falls under) then when its calculated the route, tell it to avoid the M62. Not easy to pull over and do this when your on a motorway!

So here's to hoping it'll make it into TTNAV3!

Fingers crossed!
Clem

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