Crowdsourced shipping or crowdshipping is a promising contender for sustainable parcel delivery services due to the potential to consolidate freight trips with pre-existing passenger trips. However, the opportunity for private persons to act as occasional carrier can also generate new trips, which could then increase traffic volumes. Previous literature has focused on the consolidation case only, and has not addressed new activity generation in crowdshipping. In this study we investigate the willingness of private persons to accept shipments based on a newly generated home-based trip and compare this to choices of occasional carriers who had already planned their travel, in this case related to the daily commute. We conduct two stated preference experiments and apply a multinomial logit model to identify preferences. Additionally, a latent class choice model is utilized to explore the existence and effect of heterogeneity in preferences. The results show that commute-based and home-based trips have
different VoT parameters and the former is higher than the latter. Parcel lockers as delivery points have a positive effect on acceptance since they allow for more flexibility in delivery times. The latent class model suggests that the distinction between low income and high-income groups is relevant; here, the low-income group has a lower value of time and is more willing to make a detour to execute the delivery. The study provides first quantitative evidence that crowdshipping can act as a potential trip generator in households and recommends that this is taken into account in passenger transportation models.