The future holds great promise for the use of autonomous vehicles. Many daily activities which require the use of extensive manpower, will soon be performed with much less human interference, if at all. City logistics is an example of one such arena, which will most surely benefit from the introduction of autonomous vehicles. Autonomous vehicles will replace human couriers in the near future, and conduct delivery tasks. Given the current trends in the freight industry, this will probably be integrated with the use of platoons, which has recently gained an increasing interest in the freight sector. In this paper we present an urban freight delivery system, which is based on the use of autonomous connected platoons. In the presented system, autonomous vehicles carry out delivery tasks, traveling from an origin depot to a customer, by joining platoons along the way, which bring them closer to their destination. Many issues can be analysed with respect to the proposed system. In this paper, we choose to focus on the travel time issue. In particular, we examine the effects different platoon configurations (total number of platoons in the network and their size) have on the travel time of the vehicles performing the delivery tasks. In order to examine the proposed system, a traffic microsimulation is used. A case study is presented, demonstrating the effects of varying the platoon number and size on the travel time. The results show a relation between the configuration of platoons and the travel time, especially with respect to the delay in intersections, and the waiting time while switching platoons. © 2017 The Authors. Published by Elsevier B.V.