NASCAR relies on Ably to deliver live experiences for millions of race fans worldwide

In the world of motorsport, NASCAR differentiates itself by enabling fans not only to watch, but to virtually experience the race via their Drive platform. Drive offers access to a host of engaging features from in-car video streams to live dashboard data, including speed, RPM, break, throttle, and fuel percentage.

With 40 cars whirring around the track up to 200mph, quick reaction times from drivers are essential. Consequently, cars emit 100 data points 120 times per second, contributing to more than a terabyte of high-frequency data per event.

For the Drive live dashboard feature to keep pace with the race, telemetry data must be broadcast to users efficiently. However, with the number of users fluctuating significantly depending on the popularity of the race, provisioning servers with enough resources to handle their inefficient long polling-based architecture became a challenge that detracted from feature innovation. 

What’s more, abrupt and unexpected events, such as crashes or close finishes, often result in sudden spikes in viewership as fans rush to stay updated about the situation. Previously, this required an engineering resource on standby to monitor and provision extra capacity if needed.

Here’s how NASCAR architected their system to stream realtime dashboard data from the track to Drive end-users with Ably: 

During a race, cars transmit ECU sensor data such as RPM, tire pressure, temperature, throttle position, and more to a local server over radio frequency. Race teams can then read this data directly from the server to monitor the car and make strategic decisions about things such as pit stop timing.

While each car generates over 100 data points every 8 milliseconds, transmitting this immense amount of information to end users would not be cost-effective, nor would it provide a good user experience. Realistically, consumer devices cannot process such a large volume of data and it would rapidly deplete the device's battery life and data plan.

Accessing the same local server as the teams themselves, NASCAR frequently queries the latest telemetry data to produce a subsample of dashboard data, which is broadcast twice a second with Ably Channels.

While some parameters like acceleration might have changed since the last message, others like steering angle (on a straight, for example) might not have. To reduce message size and optimize bandwidth and costs, NASCAR takes advantage of Ably delta compression, a switch that, once flicked, ensures Ably SDKs only send the difference between the previous message and the new one, reducing bandwidth and decreasing latency in some cases. 

NASCAR Drive offers a compelling alternative to traditional broadcasting subscriptions by providing a unique and comprehensive view of the race. Additionally, those already subscribed to a broadcaster can use the app as a second screen to supplement the broadcast - enhancing their viewing experience with realtime, in-depth insights.

By tapping into the concept of second-screening, fans don’t just passively watch the race, they interact with them. Instead of succumbing to the broadcaster’s decision of what to showcase, viewers can personalize their experience and closely follow their favorite driver. This not only keeps fans hooked from start to finish, but also provides a unique perspective they can share and discuss on social media, keeping the conversation going well after the race has finished.

Scalability issues, particularly during sudden and unpredictable fluctuations in connections peak times, have been addressed with Ably, allowing NASCAR to manage sudden influxes of users effectively. This has not only improved operational efficiency, but it has also bolstered user experience, ensuring that data is always available when users need it.

By leveraging Ably’s idiomatic and well-documented SDKs, NASCAR Drive successfully moved away from the binary black box solution they inherited, increasing developer confidence to make changes without causing regressions and to build new features.

Chad Larter, Senior Director, Technical Operations at NASCAR explained:

"We’re not just benefiting from Ably’s ability to elasticity scale, but also from the freedom their SDKs give us to innovate. We can move a lot faster and think more creatively about the user experience we want to deliver."

NASCAR are currently exploring moving their leaderboard solution from long polling to Ably, as well as prototyping innovative new features like in-app realtime content updates about the race, and a 2D map feature, which renders every car’s position, creating compelling alternative to traditional broadcasting subscriptions, providing a unique and comprehensive view of the race.