The Southwest Houston Redevelopment Authority (SWHRA) TIRZ 20 authorized Cobb, Fendley & Associates to proceed with preliminary design services for the reconstruction of Harwin Drive and Gessner Road signalized intersection and approaches on August 16, 2018. The major objective for this report is to review and evaluate existing right-of-way, visibility triangles, added capacity, traffic signals, signage and pavement markings, storm drainage systems, public utilities, pavement, pedestrian elements and street lighting within the project area and recommend comprehensive infrastructure design solutions in the form of plans, exhibits and construction cost estimates. The project is located approximately eleven miles west-southwest of downtown Houston, Texas in Council District J (Key Map© 530A).
The proposed intersection approaches for Harwin Drive features a four-lane concrete boulevard with raised median and dedicated right and left turn lanes onto Gessner Road. The proposed lane widths for all approaches will match the existing condition. Medians along Harwin Drive will vary between 1 and 5 feet wide and all corner radii at the intersection will be increased to 35 feet. The proposed Gessner Road approaches will be identical to the existing Gessner Road lane configuration. CobbFendley recommends constructing the proposed intersection with 11-inch-thick reinforced concrete pavement on an 8 inch thick lime stabilized subgrade (5% by dry weight). We also recommend constructing 7 inch thick reinforced concrete driveways over 6 inches of stabilized subgrade using 10 foot radii for driveway curb returns. Within the project limits, ADA compliant reinforced concrete sidewalks and wheelchair ramps will be provided.
See Exhibit 3 for the proposed roadway plan and profile drawings.
The proposed intersection design will be coordinated with Houston Park Board for incorporating a segment of proposed 10-ft wide concrete hike and bike trail alignment to be located along the west and south property lines of existing CenterPoint electrical substation (Gessner east ROW line and Harwin north ROW line) and continuing south along the existing CenterPoint power line fee strip located approximately 500-ft east of the Gessner Road.
Proposed traffic signals will be reconstructed and re-timed to accommodate the future lane configuration of the intersection. We recommend acquiring 4 parcels of real estate to allow for the construction of proposed dedicated right turn lanes and corner setbacks (corner clips) for underground utilities, sidewalks, and traffic signal pole foundations.
The project’s proposed storm sewer drainage system will both simplify and improve elements of the existing system. Proposed inlets and storm sewer piping will tie into the existing Harwin Drive and Gessner Road storm sewer systems and will correct several sunken storm sewer leads. The existing water distribution system is dated and deteriorating thus we recommend reconstructing approximately 1,040 linear feet of 12-inch diameter water main, 380 linear feet of 20 inch diameter water main, and all ancillary facilities and connections within the project limits. This includes transferring all existing service lines from the existing main to the proposed water mains.
Within the project limits the wastewater collection system is comprised of three separate systems. City of Houston GIMS revealed that much of the sewer mains within this area has been rehabilitated or replaced recently therefore; we do not recommend any modifications to the existing wastewater infrastructure.
CobbFendley is recommending relocation of the existing METRO bus stops impacted by expansion of the Gessner and Harwin approaches to the intersection. This includes 18 streetlight luminaires and 3 bus shelters. Coordination with both CenterPoint Energy and Houston Metro for the final location of street luminaires and bus shelters will take place during the design phase of the project.
Currently the construction cost for the project is estimated at $2.5 Million.
CobbFendley has submitted the 90% completed plans to the City of Houston awaiting design comments. We anticipate finalizing the bid ready construction documents by early Spring 2020 and advertise the project for construction by late Spring 2020. Based on our experience with similar roadway reconstruction projects we anticipate a construction duration of approximately 270 days.