This paper explores a cross-layer design approach for effective data delivery in vehicular ad-hoc networks (VANETs) using IEEE 802.11p, focusing on the challenges posed by high mobility and varying network topology. It compares different radio propagation models (free-space, two-ray, and log-normal) to assess their impact on received signal strength (RSS), packet delivery ratio (PDR), throughput, and delay in urban traffic scenarios. The simulations indicate that a better routing decision can enhance communication performance, especially in environments with high vehicle density.