The use of connected autonomous vehicles (CAVs) can help reduce gaps between vehicles. However, smaller gaps may cause challenges for on-ramp vehicles merging into the freeway. This study introduces several strategies that allow on-ramp vehicles to merge safely and efficiently to the mainline by providing adequate merging gaps or resolving merging conflicts in a mixed traffic environment. Eight methods are proposed to facilitate merging. These strategies are simulated in a mixed traffic environment and with different traffic characteristics, including different proportions of CAVs. The results indicate that operational performance is affected by CAV penetration rate and traffic management strategy. For relatively low freeway traffic volume, or 100% CAV penetration rate, traffic operations under the do-nothing option performs almost as well as the best traffic management strategy. However, at lower CAV penetration rates and high freeway traffic volumes, the proposed strategies are more viable than the do-nothing option.