
Ask HN: What makes great real-time, turn-by-turn navigation software? - thomas536
There are a handful of examples of open source, real-time, turn-by-turn navigation software out there. For example, https:&#x2F;&#x2F;github.com&#x2F;valhalla&#x2F;valhalla gives great turn-by-turn directions. I&#x27;m looking for best practices around navigation that will tell you to turn right in 300 feet as you&#x27;re driving.<p>I&#x27;m curious about the high level, non-obvious gotchas in making them really useful to match current best offerings. Things like smoothing of gps (specific to the use case), better estimation techniques for current position&#x2F;speed between gps updates, best practices around time estimation to next turn given current (estimated) position&#x2F;speed, how best to determine when to reroute (how far is too far off route, how long to wait until rerouting), cheats people use to paper over bad data, etc.<p>Thanks!
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jasonkester
Let me control the zoom.

Sometimes I want to see my whole route. Sometimes I want to see city streets.
Sometimes I want to see as far as the next big city. Only I know which of
these I want to do.

But you know what I never want to see? A beige screen with a blue line across
it representing the 50 feet either side of my car.

That, however, is what every modern satnav insists that I see for the entirety
of my trip. If I dare zoom out, it'll either zoom me right back in after five
seconds, or stop tracking along with me so that the little car icon drives off
the side of the map and I see a little "recenter" button that will zoom me
back into that "1m = 1m" view that it loves so much.

It's maddening.

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ian0
I can only comment from a user's perspective but the issues I face with google
maps directions:

\- The warning to turn a few hundred meters out works, but I find in dense
urban areas is that the "turn now" message is delivered too early sometimes.
Where there isn't much of a gap between turns It can occasionally lead you to
make a turn down the wrong (earlier) road. Low speed, heavy traffic situations
are worst.

\- It frequently leads you through backroads here (Jakarta, Indonesia), which
often dont have much space for a single car. Allowances for developing cities
need to be made given the width of roads. Gmaps has improved considerably in
this area over the past few years but its still problematic.

\- Heavy traffic estimations (eg where the traffic is a dark red on gmaps) are
far too conservative for this and other similar asian cities. It's like it
hits a theoretical max-time that a car can be queuing without taking into
account cities with insanely bad traffic :P

\- It may be annoying for some, but id appreciate a "last rest stop for xx km"
message when on the highway if its above a certain distance (say 40km) :)

\- Gmap specific: It's very unclear whether the navigation is on mute or not

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kstenerud
1\. Eliminate chattiness. I've had the Google navigation system talk for 30
seconds straight as I'm trying to figure out which lane to be in, so that it
can recite every single word on a sign i passed.

2\. Say which way I'll be turning later on so that I'm not stuck waiting for
the last minute turn left, crossing 3 Lanes of traffic.

3\. Only the essentials on the screen, with more important stuff bigger. Don't
keep everything proportional if it makes it harder for a busy driver to see
what he needs to see.

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hcho
Be "locale" aware. All the navigation software insist on using street names.
In the UK that doesn't help as street name signs are generally located in the
street. By the time you can see the sign, it's too late to make a turn.

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matt_the_bass
I’m a fan of including landmark based directions such as “turn left in 300m
after the church”.

I also like knowing the next directions after the current directions.

I also like clear display of which lanes to be in for a turn.

