Between the A7 junction at Zurich and the A7 junction at Drachten, the route runs roughly sixty-five kilometers across Friesland, threading past Harlingen, Franeker, Dronrijp, Marssum, and the provincial capital at Leeuwarden. The first 1.7 kilometers from the Zurich interchange are full A31 motorway. The next seven are expressway. Then the road necks down to two lanes for three kilometers as it lifts itself over Harlingen on an elevated section. After Harlingen, eighteen kilometers of proper motorway sweep past Franeker and Dronrijp before the A31 hands off to the N31 at exit 22 for Marssum. From there, traffic crawls around Leeuwarden on at-grade intersections, signals, and roundabouts before the last stretch finally widens to four lanes — a widening that was not completed until 2008.

The reason the road looks like a compromise is that it is one. Harlingen has been a serious North Sea port since the nineteenth century, and there were proposals as early as 1845 to make it a passenger-and-freight hinge between the Netherlands and the wider world, with railway connections including one running along what would later become the Afsluitdijk. Most of those connections were never built. The route that did emerge was numbered as part of European route E10, then later renumbered as the more modest N31 — a change that local commentators have long read as a quiet downgrade of Harlingen and the Frisian-Groningen north. In a country where the prestige routes are A-numbered — A1, A2, A7 — a hyphenated A31/N31 reads, on a road sign, as a region that almost mattered.

None of that is obvious from behind the wheel. What you notice instead is the sky. Friesland is so flat and so wide that the horizon is mostly weather — stacked cumulus over the IJsselmeer behind you, a single church tower rising out of a field of dairy cattle ahead. The motorway sections give you the long quiet of a Dutch highway: green verges, white-painted bicycle paths in the middle distance, the occasional thatched smock mill turning slowly off to one side. Then comes the squeeze through Harlingen, where brick warehouses and old harbor cranes crowd the elevated lanes. The road climbs, the city presses close, and you remember that this was a serious port before it was a problem to be engineered around.

Leeuwarden announces itself with the Achmeatoren, the 115-meter office tower that is the tallest building in northern Netherlands and visible from a long way out across the polders. The N31 funnels you in through a string of roundabouts and traffic lights that feel almost suburban, a reminder that this is still, by Randstad standards, a small city in a quiet province. Then the road releases you onto the final widened section toward Drachten, and the rhythm changes again — four lanes, grade-separated, properly fast. The whole route, end to end, is a sixty-five-kilometer essay on how infrastructure encodes priorities: which towns get bypassed, which get squeezed through, and which finally get the motorway they were promised.