For most open roads, the maximum legal speed limit for a car towing a trailer is lower than for the same car driving solo, and it depends heavily on the country and road type. Because laws vary by jurisdiction and there is no single global rule, the only fully reliable answer is to check your local road authority’s towing-specific speed limits.

Typical limits by country

Here are some common examples to give a rough idea of what “maximum legal speed” often looks like when towing a trailer on the open road:

  • United Kingdom (cars towing trailers or caravans)
    • 50 mph (80 km/h) on single carriageway roads.
* 60 mph (96 km/h) on dual carriageways and motorways.
  • New Zealand (light vehicles towing trailers)
    • 90 km/h maximum on the open road, provided there is a rigid connection between vehicle and trailer.
  • Many European countries (general pattern, varies by country)
    • Often between 70–90 km/h outside built-up areas and 80–100 km/h on motorways when towing, with some countries allowing higher speeds if special permits or stickers are used.

Because enforcement and details differ (weight limits, trailer type, permits, weather, etc.), always:

  1. Check your national or state transport/road authority website for “towing speed limits” or “trailers/caravans”.
  2. Verify the specific road type (open road, motorway, dual carriageway, rural highway).
  3. Follow posted road signs if they set a lower limit than the general towing maximum.

TL;DR: A very common maximum for cars towing trailers on open roads is around 80–90 km/h (50–55 mph), but the exact legal limit depends on where you are and the type of road, so you must confirm with your local official road rules.

Information gathered from public forums or data available on the internet and portrayed here.