Rust is Good for Cars! Volvo is Stepping on its Gear

Software engineers at Volvo see a bright future for Rust in Volvo! Let's find out why

Rust is a multi-paradigm, general-purpose programming language designed for performance and safety, exceptionally safe concurrency. Rust is syntactically similar to C++ but can guarantee memory safety without garbage collection. Rust has been called a systems programming language, and in addition to high-level features such as functional programming, it also offers mechanisms for low-level memory management.

Software engineers at car maker Volvo have detailed why they are fans of the Rust programming language and argue that Rust is actually "good for the car".  Everyone loves Rust, from Microsoft's Windows and Azure teams to Linux kernel maintainers, Amazon Web Services, Meta, the Android Open Source Project, and more. And now it seems it's time to add software engineers at Volvo to that list.

First appearing in 2010, Rust designers refined the language while writing the Firefox browser engine. It has gained popularity and investment from the industry, including Amazon, Discord, Dropbox, Facebook (Meta), Google (Alphabet), and Microsoft. Repeatedly, Rust has been voted the "most loved programming language" in the Stack Overflow Developer Survey.

As Rust is built by its community, each major decision in Rust starts as a Request for Comments (RFC). Everyone is invited to discuss the proposal and to work toward a shared understanding of the tradeoffs. Though sometimes arduous, this community deliberation is Rust's secret sauce for quality. Therefore, it is important to bridge among communities. The future contact person on the AUTOSAR side is a lucky catch for this task.

Julius Gustavsson, a technical expert and system architect at Volvo Cars Corporation, explains "Why Rust is actually good for your car" in an interview on Medium with fellow Volvo software engineer, Johannes Foufas. Rust is a relatively young language that helps developers avoid memory-related bugs that C and C++ do not automatically do, hence Rust's growing popularity in systems programming. According to Microsoft and Google's Chrome team, memory-related bugs are the most common severe security issues.

Gustavsson says he started bringing Rust into Volvo with the Low Power node of the core computer.

Gustavsson sees a bright future for Rust in Volvo but that doesn't mean using it to replace already working code that's been adequately tested. He notes that new Rust code can co-exist with "almost arbitrary granularity" with existing C and C++ and that it could make sense to cherry-pick parts to rewrite Rust if that component needs cybersecurity.

"We want to expand Rust here at Volvo Cars to enable it on more nodes and to do that, we need to get compiler support for certain hardware targets and OS support for other targets. There is no point in replacing already developed and well-tested code, but code developed from scratch should definitely be developed in Rust, if at all feasible.

That is not to say that Rust is a panacea. Rust has some rough edges still and it requires you to make certain trade-offs that may not always be the best course of action. But overall, I think Rust has huge potential to allow us to produce higher quality code up front at a lower cost which in turn would reduce our warranty costs, so it's a win-win for the bottom line," he said.

Volvo isn't the only automaker interested in Rust. Autosar, an automotive standards group — whose members include Ford, GM, BMW, Bosch, Volkswagen, Toyota, Volvo, and many more — in April announced a new subgroup within its Working Group for Functional Safety (WG-SAF) to explore how Rust could be used in one of its reference platforms. SAE International also set up a task force to look at Rust in the automotive industry for safety-related systems.