Harborside Drive Traffic Study

CobbFendley performed a corridor study for 3.6 miles of Harborside Drive located in the Port of Galveston, Texas. Harborside Drive has high heavy truck traffic and high pedestrian volumes associated with the port and cruise terminal operations. As such, this study evaluated multi‐modes of transportation, including vehicles, pedestrians, heavy trucks, and buses. The purpose of the study was to evaluate the phasing, timing, and progression of 12 signals, speed zones, property access, pedestrian operations, ADA deficiencies, impacts of planned future developments, and to provide access management recommendations.

To perform the analysis, data was collected, which included 7-day traffic and pedestrian counts, speed counts, and crash data from the Crash Records Information System (CRIS). Several field visits were performed to understand vehicular and pedestrian flows. Alternatives for evaluation were defined through working meetings with the project stakeholders and CobbFendley staff. After data was collected, field visits performed, and alternatives defined, the analysis was performed using Synchro software. Synchro aided in evaluating existing conditions, making signal timing, and phasing recommendations, evaluating measures of effectiveness, such as travel time, speed, delay and LOS, making progression recommendations, and developing pedestrian crossing times which were based on pedestrian demand.

Safety evaluations were performed by summarizing the crashes using CRIS data and comparing conflict points between recommended alternatives. Traffic signal warrant analyses based on the TMUTCD were performed at intersections for signalization recommendation purposes. From the speed counts, the 85th percentile speed for Harborside Drive was determined. The counts collected were the basis for recommending that the speed limit be reduced to 35 mph.

One challenge encountered on this project was right-of-way constraints. Due to the congested location of Harborside Drive, the total width of the roadway could not be altered. CobbFendley reviewed different alternatives for the length, width, and type of median. Our team performed a cost-benefit analysis to help further refine the preferred alternatives. Additionally, we showed the alternatives in a general diagrammatic form using MicroStation with aerial photography as a background image to aid stakeholders in choosing the preferred alternative.

Due to the higher volumes of pedestrians versus vehicles, signal timing, phasing, and progression along the corridor was a challenge, as priority was given to pedestrian traffic. As a solution, adjustments to the system corridor timings to address progression for vehicular flow was performed. CobbFendley also performed sight distance analyses at the intersections along Harborside Drive to improve safety. Pedestrians had unique needs for infrastructure to accommodate their luggage and needed more time to cross the road. These challenges were solved by installing wayfinding signs, which instructed pedestrians where they could safely cross the road, and by installing a raised median for access management, which discouraged pedestrians from performing mid-block crosses, reducing conflict points for vehicular traffic. A traffic signal at the unsignalized location of 33rd Street was also recommended to improve safety and traffic circulation.

Utilizing CobbFendley’s in-house surveying and mapping team, a topographic survey confirmed that only minor modifications allowed for the desired improvements to be constructed with little impact to existing utilities and existing traffic signals. This resulted in a major cost savings.

Stakeholders included TxDOT, the Port of Galveston, the City of Galveston, and the local business community. Constant communication and open dialogue between the stakeholders and CobbFendley staff aided in the project success. These open lines of communication led to healthy discussions of different alternatives, recommendations and ultimately the selection of the preferred alternative.