The Jan Koudstaal Dijkloop is an October road race in Schoonhoven, South Holland. The half marathon is the longest distance offered. Runners begin and end at Avantri Stormbaan. The event also includes a 1.5 km youth run, a 6 km race, and a 10 km race, catering to children, shorter-distance runners, and half-marathon participants. The organizing club is affiliated with the Atletiekunie. Entries have recently increased significantly, with the half marathon attracting much of this additional interest.
The course runs along the dike next to the Lek river, utilizing the open green outskirts of Schoonhoven instead of a city-center circuit. The half marathon features approximately two kilometers of semi-paved ground and several cattle grids, requiring slightly more caution underfoot compared to a standard asphalt race. Youth participants receive a medal, while those completing the 6 km, 10 km, and half marathon are given a sponsor's keepsake. Logistical provisions include two aid stations on the half marathon course, medical assistance, changing facilities, showers, and nearby parking.