In my last post, I created a dashboard that shows the estimated arrival time of buses at specific stops. After using it, I was curious to see how accurate those estimates are.
So I have created a new project:
As always, everything is opensource and available on my github page.
This project consists of two parts:
- A capture script that queries Availtec’s API every 30 seconds for the estimated arrival time and stores them in a local database
- A graph script that generates pretty visualizations from the captured data.
Here is an example of the Route 44 Inbound at St. Vincents Hospital for Birmingham, AL’s transit system.
Each “block” is a bus trip throughout the day. The dark black line represents the actual time the bus arrived at this stop. The dark blue line shows when Availtec estimated the bus would arrive at that specific time.
Ideally, the dark blue line would be as close as possible to the dark black line.
From the image above, we can see that the 4th trip, from 10:44:17 to 10:46:17 had the best estimate. From 10:00am to 10:50am, Availtec estimated the bus would arrive ±30 seconds from when it actually did.
We can also see that the trip after it, had the worst estimate. From the time the trip started, just before 10:50, until around 11:20, Availtec was estimating the bus would arrive at 11:32, when it actually came at 11:38. It wasn’t until about 11:25, that the system suddenly corrected and started estimating a more realistic time.
This project works with any bus system that utilizes Availtec for real time tracking. You can leave the capturer program running in the background for days, then generate graphs based on that historical data. The graphing script allows you to specify which stops, routes, and days to plot.