Successful cycling promotion ultimately depends on high-quality facilities. In order to increase the modal share of cycling in the German speaking countries the existing cycling network has to be substantially improved with regard to quality and connectivity. The effect of such interventions can hardly ever be sharply determined, due to numerous inter-dependencies, rebound effects and correlations. Hence, it is difficult to measure the contribution of single interventions to mode shifts. Against this backdrop it is necessary to consider potential co-factors in the estimation of expected effects. This should enable an optimal use of financial resources for an effective and efficient mode shift towards cycling.