Improving bus times

3 min readMar 30, 2021


Can you rely on bus countdown screens?

Over the last year, we’ve been hard at work at solving one of the biggest issues our customers face: when will their next bus arrive?

Like most public transport services, we rely on the bus companies themselves to provide accurate arrival times for each of their vehicles. But there’s always room for improvement.

In January, the UK’s Department of Transport launched live bus locations through it’s Bus Open Data Service (BODS). As of March 2021, this includes tens of thousands of bus locations throughout England. This is great in so many ways, but it raises a question: how do you take a bus location and work out when it will arrive at each stop on its route?

You could of course do it the simple way: if the bus is currently at position X, which is way behind position Y (where it should be, according to the published schedule), the bus must be Z minutes late. Add Z to the scheduled arrival time and bam! — real-time arrival predictions.

But that’s just not good enough.

Every city has its quirks: there’s always certain streets, roads and intersections which flare up with traffic in predictable ways, messing up the bus schedule. A bus which turns up on time at 2pm faces different conditions than one that arrives at 5pm - usually that one set of traffic lights which lets twice as much rush-hour traffic flow north-south than east-west. How do you factor that in?

Here’s how we do it: we store all of the bus locations in a huge database, along with the exact time they actually arrived at each stop on any given journey. Then you look at a bus journey starting now. If the bus arrives 10 minutes late at stop X every Friday night between 5 and 6pm, you can comfortably predict it will be 10 minutes late again this Friday, even if the simple location-to-arrival-time calculation we used above tells you it will arrive in 2 minutes.

Simple live tracking (blue) vs exact-match (green)

We also use other buses in the area as a guide: are a majority of the buses going down this one congested road arriving late? If so, you can predict the bus you’re looking at will be late too.

It’s the difference between showing when the bus is likely to arrive and having the confidence to say this bus is on time or this bus will be 7 minutes late. It’s the difference between getting wet standing at a bus stop and staying in your home for another few minutes to avoid the rain.

Over the last year, we’ve rolled this out to select cities —Nottingham, Liverpool and Brighton in the UK, along with New York, Sydney and San Francisco, with more cities levelling up every week.

Soon, your Whiz departure board will be awash in greens (that’s on time) and oranges (that’s late). Hopefully, not too many oranges!

For us, it’s the next step in providing consistently accurate and useful information to the millions of commuters who have chosen Whiz to guide their travel, and it’s thanks to the hard work of all the bus and train companies around the world, who open up their schedules and the locations of their fleet that make it possible.

Until next time, happy commuting!




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