Faster vs Fastest

[Coddiwompler]

I expect this has been explained elswhere, though I have looked and cannot find it. In the useful guide there's reference made to using the 'Faster' routing calculation mode, but using my Mac Air and Basecamp I only have Fastest, Shortest Distance and Curvy Roads. Is there a 'Faster' option rather than 'Fastest' or is this a PC vs Mac Basecamp difference?

... and would it make a difference?

Thank you

[Peobody]

but using my Mac Air and Basecamp I only have Fastest, Shortest Distance and Curvy Roads. Is there a 'Faster' option rather than 'Fastest' or is this a PC vs Mac Basecamp difference?

I would say it is a PC vs Mac difference because the PC definitely has Faster Time, Shorter Distance, and Curvy Roads.

... and would it make a difference?

Faster Time will route over faster roads. The algorithm does not appear to take into consideration whether the faster roads will result in more time, more distance, or both (they often do).
Shorter Distance has a reputation for cutting through parking lots. I have never tried it due to strong recommendations against it.
Curvy Roads is an interesting one. If you normally ride on secondary roads, then letting Basecamp create a route using Curvy Roads is worth it just to see what the end result is.

Be aware that there is an issue when the default route preference set in the satnav is different from the one set in a route. IIRC, such a mismatch will trigger a calculation of the route by the satnav, which may change the route. I'm sure someone will be along to expound on this.

[Coddiwompler]

Thank you

[lkraus]

Basecamp actually makes decent choices to keep travel time short with Faster Time. The 590/595 did pretty well also. It is the XT that tends to disregard total time when selecting "faster" (major) roads. It will add lots of time and distance just to use a highway when there is a shorter and quicker road available, even if the speed limits are the same. If you don't let the XT recalculate, the Basecamp Faster Time routes will work well.

Shorter Distance is great if you like to travel a maze of residential streets and alleys, stopping at each corner every time your route passes through an urban area.

Curvy Roads can be interesting to consider, but I think you need to add lots of via points to keep the route intact when transferred to a Zumo, which does not recognize Curvy Roads. I believe it will recalculate the route using whatever faster/shortest preference you have set on the GPS. It has been many years since I tried it, but I believe it also added a lot of frustrating turns in towns just to add a "curve".

I just always use Driving mode/Faster Time, avoid recalculations, and make my own choices to keep the routes efficient in urban areas and interesting in the rural areas.

[jfheath]

I have a 'theory' about the XT's Faster Time Algorithm.

This is just an idea. I haven't seen it fall over yet, but I haven't done much riding recently.

if there is a faster road nearby which can be used to get you to the next route point, it will head for the faster road If the faster road is closer than the route point.

Otherwise it uses the roads which lead to the routepoint


Its hard to prove, because in order to see how it behaves, the XT has to calculate the route. If you deviate and take the preferred route rather than its fasrer route, the routing is affected by what I referred to as RUT behaviour - going back to the point of deviation.

But having that in mind helps to place shaping points. If there is a fast road nearby, make the next shaping point be closer than the fast road.

[Peobody]

Basecamp actually makes decent choices to keep travel time short with Faster Time.

I won't go so far as to say "decent". I prefer secondary and tertiary roads so a common route creation challenge for me is to keep the route on a road that runs parallel to a faster road if there are connections between the two. It can take at least one well placed route point between every connecting road. Place a route point too far ahead and Basecamp will route you on the faster road, divert off of it and backtrack to that route point, u-turn, then continue to the next route point. Still, it is better than the XT. You can have a situation like this tamed in Basecamp but if the XT recalculates the route there is no telling what that stretch of the route will end up looking like.

if there is a faster road nearby which can be used to get you to the next route point, it will head for the faster road If the faster road is closer than the route point.

This logic makes sense if no consideration is given to the travel time and distance to and from the faster road. The XT does not appear to give that consideration.

[jfheath]

It can take at least one well placed route point between every connecting road. Place a route point too far ahead and Basecamp will route you on the faster road, divert off of it and backtrack to that route point, u-turn, then continue to the next route point. Still, it is better than the XT. You can have a situation like this tamed in Basecamp but if the XT recalculates the route there is no telling what that stretch of the route will end up looking like.

I'm pretty sure that you have a technique to deal with this, @Peobody but for any else reading the thread ....

I have seen XT users describe a technique where they keep adding shaping points along a road until the route stops diverting - but you end up with far too many in my opinion. A better way for a single stretch of road is to place 2 shaping points eg at about 1/3 and 2/3 distances - perhaps slightly smaller gap in the middle.

In towns, this technique leaves open the opportunity for the XT to short cut a corner, but these are easy to spot and ignore - especially if the track displayed under the route.

[Oop North John]

I have a 'theory' about the XT's Faster Time Algorithm.

This is just an idea. I haven't seen it fall over yet, but I haven't done much riding recently.

if there is a faster road nearby which can be used to get you to the next route point, it will head for the faster road If the faster road is closer than the route point.

Otherwise it uses the roads which lead to the routepoint

Its hard to prove, because in order to see how it behaves, the XT has to calculate the route. If you deviate and take the preferred route rather than its fasrer route, the routing is affected by what I referred to as RUT behaviour - going back to the point of deviation.

But having that in mind helps to place shaping points. If there is a fast road nearby, make the next shaping point be closer than the fast road.

My theory is that the XT is lazy when looking for a faster route, especially if it's recalculating an imported / saved route.

My theory is that it uses the roads hierarchy when looking for routes and if it finds a route using what it considers the "fastest" one, it'll use that, and stop looking at alternates. In Spain last year I was heading along their version of an "A" road after going off the planned route, and the XT basically was going to take me along two sides of a triangle ie < I zoomed out, saw a "B" road going between the two end points of the < and almost immediately, the XT was routing me along the "B" road. IIRC there was about 20 minutes difference between the two routes.

[Peobody]

A better way for a single stretch of road is to place 2 shaping points eg at about 1/3 and 2/3 distances - perhaps slightly smaller gap in the middle.

Yup! That emphasizes my point about Basecamp's preference for faster roads and the 'hoop jumping' that is sometimes needed to create the route that you want.

[jfheath]

Curvy Roads can be interesting to consider, but I think you need to add lots of via points to keep the route intact when transferred to a Zumo, which does not recognize Curvy Roads. I believe it will recalculate the route using whatever faster/shortest preference you have set on the GPS. It has been many years since I tried it, but I believe it also added a lot of frustrating turns in towns just to add a "curve".

One of the Zumos recognised Curvy Roads as a routing preference. I think the 590. The XT doesn't as @lkraus correctly suggests. But any routing preference that is not recognised by the XT - it uses Faster time as the calculation mode.

Any vehicle profile from BC that it doesn't recognise, the XT defaults to using Motorcycle, and it will use those parameters stored in the XT motorcycle preferences if it ever has to recalculate the route.

This can cause a lot of issues for the unwary. The route was built (say) to allow ferries. Basecamp sends and the XT receives the exact route and follows it. Any recalculation by the XT and it loses the BC route and uses the avoidances that have been stored for the motorcycle - which avoids ferries (say). Suddenly by going slightly off route, the XT is behaving weirdly - 'cos it now has to find a new route to avoid the ferry that it had been heading for.

More info on how the XT behaves with profiles / routing preferences from BC and the settings in the XT are described here.
Its too complex - especially since the 660, 590, 595, and XT all have slight differences. The 590, I think it was, accepted Curvy roads from BC. The XT does not.

I just set no avoidances in BC. and XT. If I want to avoid motorways I use shaping points to stop it from using them. Part of the reason for this is that I don't know how the BC categories match with the Uk Zumo categories - so I avoid the problem rather than attempt to solve it !

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