Smartphone sensing enables efficient Time-of-Arrival (ToA) estimation of moving cyclists towards traffic lights in a Smart City. GPS sensors locate the actual position of cyclists on their way to traffic lights. Since the constant use of GPS sensors drain the battery of the smartphones there is a need of efficient energy consumption techniques. In this paper we propose a velocity based ToA estimation system to face the GPS energy consumption inefficiency. In addition we aim to enable efficient cycling in Smart Cities by turning traffic lights to green proactively thus achieving overall citizen's wellbeing.