This thesis proposes a modeling framework to characterize equilibrium traffic flow relations for heterogeneous traffic composed of both standard and Cooperative Adaptive Cruise Control (CACC) vehicles, capturing the impact of CACC market penetration and vehicle arrangement within a lane. The resulting parameterized fundamental diagram is then integrated with the first-order macroscopic traffic model, creating the ability to characterize operational performance on a network for heterogeneous traffic with varying CACC market penetration. This first-order approach is demonstrated through an illustrative case study which considers a small network with time-varying demand, temporary capacity reductions, and CACC market penetration ranging from 0.0 to 1.0. The results indicate that maximum throughput initially decreases as CACC traffic is introduced, but eventually improves significantly for CACC market penetration rates above 0.4. Additionally, they show that when an incident abruptly reduces road capacity, introducing even a small fraction of CACC vehicles reduces the speed at which the congestion wavefront propagates upstream