Pike: To Exit or Not to Exit

https://tomjohnell.com/pike-solving-the-should-we-stop-here-or-gamble-on-the-next-exit-problem/

by dnw • 5 months ago

67 32 5 months ago

My phone is littered with apps like these, which seem well designed to address a very specific problem which I don't have very often. The problem is remembering the app's there 3 or 6 or 9 or 18 months later when it would actually be useful to me.

Affric• 4 months ago

I always think that the goal of apps like these is build userbase and then get acquired, like darksky or waze: the big providers realise they have missed a trick and then it becomes the default.

tbyehl2• 4 months ago

"Needed tens of dollars of rental compute" isn't much of a moat to get acquired instead of copied.

I loath Waze. Its idea of shortcuts are terrible, its search routinely suggests things hundreds of mile away ahead of the match that's nearby, and sometimes I go through an area of intermittent service where it just decides to stop routing without giving a heads-up.

But Waze is so much better at accurately alerting me to police than my Valentine 1 was that I never even bothered mounting it in my latest car. Google supposedly integrates that data for years now but every time I try it comes up short. Google and Apple Maps are better in every other way, but for me at least, that one feature of Waze is a massive moat.

vmilner• 4 months ago

I thought this was going to be an article by Rob Pike on control flow in golang...

jhbadger• 4 months ago

Or the (mostly forgotten) scripting language Pike (derived from the internal language of a MUD) https://en.wikipedia.org/wiki/Pike_(programming_language)

cestith2• 4 months ago

I was prepared for a debate on calling _exit() vs exit() vs no explicit exit in Pike. This app is pretty interesting, too though.

thiscatis• 4 months ago

I would have loved this for my road trips in the US. From the other apps it was never clear whether this was a restaurant or a gas station where it's next to the highway (a quick stop) or I had to drive a mile into a town and find it. Perhaps it has improved since then (this was 2015-ish). Congrats on building this!

kper1337• 4 months ago

As an european (Austria) that never have been in the US, can someone please explain to me what exit left and exit right mean?

In Austria, you have usually one exit. Alternatively, there might be a roundabout.

Pyrodogg• 4 months ago

If unspecified, 'exit' would mean 'exit right' to the right side of the traffic flow. In dense urban areas it might make sense for geography or cost reasons to put it on the left in which case youll see "Exit Left" to make sure people know to be in the 'fast lane' in preparation to leave the highway since it departs the highway exceptionally on the left

I-94 and I-35E in St. Paul, Minnesota comes to mind. You just merge left onto the other highway if you need to change.

givc• 4 months ago

In US highways the exit ramp off the road is usually on the right, but is some cases the exit is on the left, especially in areas where the highway is elevated or in crammed downtowns. The left lane is also usually the “passing lane” and cars drive faster than on the right, so if there is a left exit and you’re cruising on the right line, you have to know in advance to safely move over to the left

tylerflick• 4 months ago

Also High Occupancy Lanes will sometimes have their own exits on the left side.

rdtsc2• 4 months ago

It’s still one exit but sometimes it’s on the left side. That is, you have to get in the left lane and then exit from there.

tjohnell7• 4 months ago

Hi - author of Pike here. You have it right. I don't think the current UX is perfect though. Clearly it's confusing folks!

Squid_Tamer• 4 months ago

While (relatively rare) left-hand exits are a thing in the US, I don't think that's what the arrows on this app is showing. The screenshot appears to be showing a single exit.

The arrows probably tell you whether your first turn will be a left or a right immediately after leaving the interstate. Many exits have two lanes, one for left turns and one for right turns onto the connected surface street. You have to know which exit lane you want to be in.

On a road trip, gas stations and fast food to the "right" of your travel direction on the interstate are slightly preferable because you don't have to wait for any left-turn signals. The US allows you to turn right at a red traffic light as well, saving even more time.

mwillis• 4 months ago

A six-week road trip sounds amazing. A six-week road trip with lots of interstate driving does not.

tjohnell7• 4 months ago

Author here - I agree with you :)

tjohnell7• 4 months ago

Hi all - author of Pike here. Happy to answer any questions.

sbecker• 4 months ago

Hi, great write up and very cool project! I was wondering how you arrived at the idea to use OSRM and pre-computing the drive time from every exit to every POI. Was that something you learned existed along the way? Did Claude/codex point the way to this?

tjohnell7• 4 months ago

Hello, I appreciate the kind words. When I realized that radial search just wasn't going to be accurate (and potentially harmful given people might exit onto another interstate thinking they could grab some Wendy's), I posited to Claude: "I need to understand reachability of a POI from an exit, reachability being defined as driving time less than X amount of time". Claude then suggested two open-source projects: Valhalla & OSRM. I haven't done much research on Valhalla - Claude ultimately recommended OSRM for its "simplicity" but again, I don't honestly know if that's true. Claude can definitely be credited with my decision to choose OSRM.

projektfu2• 4 months ago

Not available on Android? I do notice several other apps with the same name and different purposes on the Play Store.

tjohnell7• 4 months ago

No Android app - however, using the current app as the spec, it would be interesting and fun to take on creating the Android version. I really don't believe it would be that hard. Stay tuned.

jmx02• 4 months ago

Hi Tom, this app looks great! Would you consider making it available in App Store regions outside the US?

(I understand it's meant for US drivers but e.g. my Apple Account predates my move to the States)

tjohnell7• 4 months ago

Hi jmx, I hadn't considered that scenario. I'd be happy to as long as Apple doesn't have me jump through too many hoops. I don't mind a few hoops though.

nicwolff• 4 months ago

Hi, using the app now and it's been great fun. (Now if my wife would actually take an exit so we could eat!)

However, we're on 290 E and it's showing me the exits that are behind us – as if it thinks we're westbound. Is there any way to convince it we're not?

jonathaneunice• 4 months ago

Love this!

Have wanted to work on a "better situational awareness while traveling" app, but haven't yet had the chance. Reachability of a POI is a great place to start, and I _feel_ that "it's a lot harder than it at first looks" aspect.

It would also be cool to:

* Become aware of local attractions. Esp. good restaurants, shops, views, hotels, hiking trails, etc. A lot of rating systems seem to give every fast food venue 3 or 4+ stars. Impossible to sift out the truly good and local / unique from the chaff.

* Become aware of time-limited events. Fairs, art shows, VFD chicken BBQs or fish fries, ... all the little "I wish I knew that was happening, I would have stopped by!" I constantly search for the local, the offbeat, the not-yet-another-corporate-outpost. But again, the chaff!

* Be able to navigate on backroads and scenic roads. Mapping apps are so hyper-focused on getting you there fast. They're not good at "get me there happy"—at least not for those of us that value the path less traveled far more than the highest-speed highway.

tjohnell7• 4 months ago

I'm also interested in your second bullet. The likelihood that you're passing by a cool outdoor event while blazing down the interstate is a lot higher than if you're staying in town. The data would be very difficult to source.

Thanks for the ideas though. Give Pike a try and let me know what you think.

Pike: To Exit or Not to Exit

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