This paper proposes an adaptive repetition control using terminal mobility to alleviate the packet collision for uplink grant-free (GF) ultra-reliable and low-latency communications (URLLC). In GF, the packet collision among mobile stations (MSs) becomes a serious problem because the grant-issuing procedure conducted in grant-based (GB) transmission is eliminated. Especially in the K-repetitions method, intra-cell interference is increased due to excessive repetitions, resulting in decreased reliability. In the proposed approach, the number of necessary repetitions is determined using fading correlation easily obtained from the terminal speed. This is because the time diversity benefit within repetitions is dependent on the fading correlation. Using the proposed repetition control, the number of repetitions can be reduced especially in the low fading correlation, alleviating the packet collision. The effectiveness of our proposed method is demonstrated in an actual multi-user URLLC scenario by computer simulations.