Dutch Cross-Country Ski Police – we’re not really sure how fast is too fast on cross-country skis
In the U.S. ski patrollers might snag your lift ticket, and if you really screw up call the police. But in most European countries, undercover policemen roam the slopes, and can fine you on the spot. In Switzerland you can be arrested or fined up to $15,000 for skiing drunk and/or recklessly, giving lessons if you’re not a certified instructor, placing others in avalanche danger, and being an ass while waiting (or not waiting) on line.
 In Sochi, Russia skiing officers successfully lobbied to patrol on snowboards, and in the case of high-speed pursuits on snowmobiles. rt.com
Grindelwald, the first European resort to have enforced speed limits, has 30km/h (19mph) speed limit posts on some trails. How do they measure that?
Swedish Ski Police