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I understand that Google Maps works out travel times based on the speed limit for the road and the current traffic on the road. (When selecting the driving function).

When using the cycling/walking function, I assume it works out the travel times by using the average walking pace(~3mph) and the average cycling pace.(~9.6mph)

But does it increase the time if your journey includes a lot of upwards hills, as you would obviously be travelling slower if walking or cycling? And does it decrease the time when there are lots of downwards hills, as you would be travelling quicker (maybe not by foot but definitely on bike)?

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    Answered on Bicycles in this question bicycles.stackexchange.com/questions/44793/… – AakashM Jul 11 at 15:50
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    If you are looking for elevation-aware routing I’d recommend brouter. Much better for cycling than Google Maps (or any other routing service I’ve tried). – Michael Jul 12 at 5:52
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    @JackU: You can also install brouter on an Android Smartphone and use it as an (offline) navigation service for osmand (my favorite navigation app for walking/cycling, works offline as well). – Michael Jul 12 at 7:11
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    To the answers, which are suggesting, that it actually does, because they reversed the route: May be it just takes the average speed from the database for that direction. Of course this speed is higher because of the the downhill. So yes, it "does" consider the downhill but it would not be working, when there wouldn't be any historical data from previous rides. – dipa2016 Jul 12 at 11:09
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    If you find that Google is generating steep or otherwise unreasonable cycling routes, you can ask them to fix it. I've done this before, suggesting a nearby flatter route in place of a very steep hill. It takes a few days, but they do incorporate the suggestions eventually. – Kyralessa Jul 12 at 11:29
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Surprisingly, it appears that the answer is YES, Google Maps does make a distinction between uphill and downhill.

I routed out a couple of bicycle rides from my home (in Germany) to a city either 90 km away (with a 700 m climb) or 60 km away (with a 1000 m climb), depending on the route taken. I then reversed both routes.

In both cases, Google Maps shows a noticeably shorter ride time for the downhill direction than the uphill one.

The 60 km route is 5h1m going up or 4h24m going down. The longer route is listed as 5h34m going up or 4h48m going down.

Of course, Google Maps doesn't know exactly how fast I ride, but I would guess you can take the percentage difference between the uphill and downhill and do some multiplication to figure out your likely actual time based on your average speed.

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    Google Maps not only consider elevation changes when calculating travel times, but tries at least to a certain extent to avoid elevation changes when using the route planner. If a flat detour is avaialble, my experience is that the route planner often suggest to go around the elevation change instead of up and down, even if the distance is slightly greater. – Tor-Einar Jarnbjo Jul 11 at 18:51
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    I wonder if feedback from location-enabled devices also factors into the calculation. For driving directions, for instance, Google Maps won't know that a particular road is riddled with potholes, or always has deer frolicking around the embankment, but they will know that a lot of cars are going 5mph under the speed limit instead of 10 over it, and on my anecdotal experience, seem to adjust their time estimates accordingly. – choster Jul 11 at 23:41
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    @choster IMHO with bikes, such feedback is impractical. With cars, you can generally assume that drivers want to get to the destination in reasonable time and if they happen to be driving slow, they are limited by road conditions. With cyclists, you never know if they are more tired than usual, or just choose to drive slowly and admire the view. – IMil Jul 12 at 0:17
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    @IMil Another factor you have, (that I don't believe Google takes into account) would be the weather as in wind direction. There is a slight grey area with cycling as like you say there are many external factors that affect the cycle times. – JackU Jul 12 at 5:50
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    There's no need for Google to perform complex and sophisticated computations. Google has lots of data to work with, elevation may be part of it, but previous history of other travelers is by far the most significant factor. Google doesn't need to know the slope of a hill, all it needs to know is that people going north go slower on this section and people going south go faster. – barbecue Jul 13 at 1:03
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No. Google Maps works a different way.

Google Maps learns travel times by monitoring the pace of other riders.

The Google Maps app "constantly" sends data about your location back to the Google servers. It knows you're on a bike, not driving, because you requested a bike route, and because your travel time is not an outlier from other people doing the same.

And that's also true for driving; though of course Google gets more data for drivers, so driving data is fresher.

Yes, really. Google "spies on you" and observes your movement, nominally for this exact purpose (but they won't refuse a subpoena in most cases). And yes, you agreed to be a lodestar for others, at some point when you clicked "agree" on a term-of-service while interacting with a Google product. You can deny Maps access to your location, but then of course, it wouldn't work at all.

This tracking is fairly continuous, even when the screen is off, which means Google knows when you stop for a break, and excludes that time from the data.

This provides a very authentic transit time without having to do deep calculation on the effect of grades, tight curves, congestion and road condition on ideal travel times. For instance if a flat, straight rail-trail is heavily overgrown with brush to where you must slow to maneuver around a thicket of overhanging branches, it captures that reality.

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    This is the correct answer. – barbecue Jul 13 at 1:00
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    This is not precisely correct, you have to specifically grant permission for this service. If you go to myaccount.google.com/activitycontrols/location you can turn on location history. When you do you will be told this- Location History saves where you go with your devices. To save this data, Google regularly obtains location data from your devices. This data is saved even when you aren't using a specific Google service, like Google Maps or Search. – Alan Dev Jul 13 at 20:54
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    Checking another road I know well with a relatively steep climb (400m altitude in less than 10km) on the other hand gives more realistic travel times (60 minutes up, 25 minutes down). There however, bicycling is prohibited, so not only is Google very unlikely to have much data from bicyclists on that road, nor do they seem able to conclude from lack of data that you are not allowed to cycle there. – Tor-Einar Jarnbjo Jul 13 at 23:23
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    This is interesting information, but I'm not seeing any evidence for it. Could you cite a source? – Kyralessa Jul 14 at 16:51
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At least for bikes it does (assuming the topographical information mentioned in the comment is available).

I just checked with two cycling routes near my home, both 4,2km long according to Google, one almost flat, the other with a climb towards the end (obviously going downhill the other direction). Result:

  1. 4,2km almost flat but slightly downhill: 14min
  2. 4,2km almost flat but slightly uphill: 15min
  3. 4,2km mostly flat (3km), but a climb towards the end (1,2km): 17min
  4. 4,2km mostly flat (3km) and going downhill at the beginning (1,2km): 12min

If these numbers are of any relevance certainly depends on your bike and your fitness level (and probably some other factors, too). I hate riding uphill and my bike isn't made for it, so whenever I had to "cycle" up the hill at the end of no. 3 I would get off my bike and push it, certainly losing more than two minutes compared to a flat route. The same goes for downhill, I doubt I was ever letting my bike run so fast I would acutally gain two minutes...

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Short answer: Yes absolutely google maps is aware of elevation changes.

Longer answer: ...but its fairly far from correct.

Example - There's a well-travelled local climb of 2.5 km and 140 metres elevation change. Its an average of 5% but is 10% at the top with a flat bit at the bottom.

Google maps predicts 13 minutes to descend and 18 minutes to climb. That's roughly 40% longer to climb than to descend, which is utterly wrong.

I personally descended in 3:25 and best climb in 10:30, for a 300% increase in climb time vs descent time.

The 20 top riders have descended in under 2:30 and have climbed it in under 6:00 minutes for a 240% difference.

So google maps should be predicting a climb in 39 minutes for a descent of 13 minutes
or a climb of 18 minutes and a descent in 7:30.

tl:dr yes google maps is aware of elevation changes and does try to take that into account, but doesn't fully account for the increased work required to climb a gradient.


Further info:

Walking is predicted to be 40 minutes to climb and 34 to descend.

Driving is predicted to be 3 minutes either way.

Link to route on Google Maps

Strava segment for uphill

Strava segment for downhill

Site is in New Zealand, near Christchurch. I'm roughly in the middle of times for riders on those segments, slower uphill and faster downhill (mass advantage there!)

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    How do your actual times compare to Google's estimates in general? I would guess that their bicycling estimates are probably based on "average" cyclists traveling without time pressure, not enthusiasts trying to get best-possible times. – dwizum Jul 12 at 13:58
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    My guess is that google uses the time of people on road racing bikes, much faster than my commuting or even fun ride times. – Willeke Jul 12 at 14:19
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    I guess all we can really say is, cyclists travel at vastly different speeds, unlike motor vehicle traffic which is generally consistent. I know many casual cyclists who are terrified by quick descents, their % differences would probably be much different than comparing the cyclists you're looking at. This is really interesting data though, it's too bad we can't learn more about the populations in strava vs how Google gets their numbers. – dwizum Jul 12 at 14:23
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    @dwizum At least in Germany, cars also travel at vastly different speeds... – gerrit Jul 12 at 22:20
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    @dwizum not super relevant, but you might like strava.com/heatmap#12.90/172.64301/-43.69822/hot/ride Its a combined heatmap of routes from strava users. Fascinating, but times and segments aren't shown. – Criggie Jul 13 at 2:01

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