The results of the 1998 to 2008 peak period monitoring of a 8-mi FasTrak section of Interstate 15 (I-15) in San Diego, California, are reported in this paper. The paper examines changes in peak period utilization and volume distribution throughout the peak with the emphasis on the level of service (LOS) offered on both high-occupancy toll (HOT) lanes and the main lanes of I-15. The study revealed that the peak period volumes on the HOT lanes (both FasTrak and carpool) strongly depend on the LOS deficit on the main lanes. Carpool participation was not hurt by the growing FasTrak volumes. The law-mandated LOS C was effectively protected by the dynamic pricing mechanism on the HOT lanes. The Congestion Pricing Project in San Diego proved able to redistribute a portion of the peak period volumes on the HOT lanes from the middle of the peak to its shoulders and now plays an important role in improving operation of the entire I-15 corridor.