In this paper, we investigate the capacity limits in a variable duty cycle VANET that uses the IEEE 802.11p standard. We show that the default value of duty cycle that allocates time equally between control and service channels leads to unbalanced performance and that the performance of typical traffic on those channels can be greatly improved by judicious choice of the value for duty cycle. We find the values of spatial density of vehicular traffic that lead to spatial saturation of network traffic. In addition, to model the distribution of the vehicles on the road segment, we used Poisson distribution, as well as Erlang-k distribution. Copyright (C) 2012 John Wiley & Sons, Ltd.