Hi Tom,
Good question, and short answer: point+ won't get you there either road surface temperature isn't shown as its own layer or graph anywhere on meteoblue, neither on the free site nor in point+.
We do model related values like soil temperature (top 10 cm) and skin/surface temperature, but right now those live in our professional weather API packages (Agro package, History API) rather than the private website products.
If you just want a rough feel for frost/ice risk for personal use, the Meteogram SNOW (temperature profile + snow cover) combined with hourly air temperature and precipitation type is probably your best bet in point+ not an exact road temp, but a decent proxy.
If you actually need real road surface temperature (e.g. for winter road maintenance or route planning), that's something we offer through our business solutions for Transport & Logistics, with route-based forecasts recalculated roughly every 10 min.
If you have any further questions on this, feel free to open a support ticket with us.