A foldable guardrail assembly is provided for selectively facilitating access to a machine component located onboard a vehicle. The vehicle has a platform with a handrail disposed thereon and located adjacent to the machine component. The guardrail assembly includes a set of guardrails pivotally connected to each other in a successive manner via at least a corresponding number of hinge assemblies. A first one of the guardrails is pivotally connected to an upright portion of the handrail via a first hinge assembly. The guardrail assembly further includes a first latch assembly provided, at least in part, on a last one of the guardrails. The first latch assembly is configured to releasably secure the last one of guardrails to the platform when the guardrails operably move into in a fully unfolded position, via the hinge assemblies, for providing access to the machine component located onboard the platform.