On my recent wanderings in Europe, I became quite enamoured by Google's latest revision of transit directions. Google has had transit directions for some time, but they have recently improved them, and linked them in more cities to live data about where transit vehicles actually are.

The result not a mere incremental improvement, it's a game-changing increase in the utility of decent transit. In cities like Oslo and London, the tool gives the user the ability to move with transit better than a native. In the past, using transit, especially buses, as a visitor has always been so frustrating that most visitors simply don't use it, in spite of the much lower cost compared to taxis. Transit, especially when used by an unfamiliar visitor, is slow and complex, with long waits, missed connection and confusion about which bus or line to take during shorter connections, as well as how to pay.

Not so any more. With a superhuman ability, your phone directs you to transit stops you might not figure out from a map, where the right bus usually appears quite quickly. Transfers are chosen to be quick as well, and directions are given as to which direction to go, naming the final destination as transit signs often do, rather than the compass direction. It's optimized by where the vehicles actually are and predicted to be, and this will presumably get even better.

By making transit "just work" it becomes much more useful, and gives us a taste of the robocar taxi world. That world is even easier, of course -- door to door with no connections and no need for you to even follow directions. But while Uber also shows us that world well in user experience, Uber is expensive, as are cabs, while transit is closer in cost to the anticipated robocar cost of well below $1/mile.

It also helps to have transit systems with passes or contactless pay cards, to avoid the hassles of payment.

Why does this work so well? In the transit-heavy cities, it turns out there are often 2, 3 or even 4 ways to get to your destination via different transit lines and connections. The software is able to pick among them in a way even a native couldn't, and one is often leaving soon, and it finds it for you.

In some cities, there is not live data, so it only routes based on schedules. This cuts the utility greatly. From a user experience standpoint, it is often better to give people a wait they expect than to do a better job but not give accurate expectations.

What's clear now is that transit agencies should have done this a lot sooner. Back in the 1980s a friend of mine built one of the first systems which tracked transit vehicles and gave you a way to call to see when the bus would come, or in some cases signs on the bus stops. Nice as those were they are nothing compared to this. There is not much in this technology that could not have been built some time ago. In fact, it could have been built even before the smartphone, with people calling in by voice and saying, "I am at the corner of X and Y and I need to get to Z" with a human helper. The cost would have actually been worth it because by making the transit more useful it gets more riders.

That might be too expensive, but all this needed was the smartphone with GPS and a data connection, and it is good that it has come.

In spite of this praise, there is still much to do.

• Routing is very time dependent. Ask at 1:00 and you can get a very different answer than you get asking at 1:02. And a different one at 1:04. The product needs a live aspect that updates as you walk and time passes.
• The system never figures out you are already on the bus, and so always wants to route you as though you were standing on the road. Often you want to change plans or re-look up options once you are on the vehicle, and in addition, you may want to do other things on the map.
• Due to how rapidly things change, the system also needs to display when multiple options are equivalent. For example, it might say, "Go to the train platform and take the B train northbound." Then due to how things have change, you see a C train show up -- do you get on it? Instead, it should say, "Take a B, C or E train going north towards X, Y or Z, but B should come first."
• For extra credit, this should get smarter and combine with other modes. For example, many cities have bikeshare programs that let you ride a bike from one depot to another. If the system knew about those it could offer you very interesting routings combining bikes and transit. Or if you have your own bike and transit lines allow it on, you could use that.
• Likewise, you could combine transit with cabs, getting a convenient route with low walking but with much lower cab expense.
• Finally, you could also integrate with one-way car share programs like car2go or DriveNow, allowing a trip to mix transit, car, bike and walking for smooth movement.
• Better integration with traffic is needed. If the buses are stuck in traffic, it's time to tell you to take another method (even cycling or walking) if time is your main constraint.
• Indoor mapping is needed in stations, particularly underground ones. Transit agencies should have beacons in the stations or on the tracks so phones can figure out where they are when GPS is not around. Buses could also have beacons to tell you if you got on the right one.
• The systems should offer an alert when you are approaching your stop. Beacons could help here too. For a while the GPS map has allowed the unfamiliar transit rider to know when to get off, but this can make it even better.
• This is actually a decent application for wearables and things like Google glass, or just a bluetooth earpiece talking in your ear, watching you move through the city and the stations and telling you which way to go, and even telling you when you need to rush or relax.
• In some cities going onto the subway means loss of signal. There, storing the live model for relevant lines in a cache would let the phone still come up with pretty good estimates when offline for a few minutes.

A later stage product might let you specify a destination and a time, and then it will buzz you when it's time to start walking, and guide you there, through a path that might include walking, bike rides, transit lines and even carshare or short cab rides for a fast, cheap trip with minimal waiting, even when the transit isn't all that good.