Designing Greater Mobility
Safety and operational efficiency were driving factors when designing the 183 South Expressway and general purpose lanes. An expressway must have a finite number of underpasses or overpasses for cross streets in order to function as such. Therefore, our design engineers could not propose a crossing at each adjacent street. Limiting signalized cross streets also optimizes the throughput for tolled and non-tolled travel by getting people to their destination faster since they don't have to wait at a light.
Various criteria detailed below were used to prioritize which cross streets remain and which ones will be eliminated. As approved by TxDOT through the environmental study process, five existing signalized cross streets were identified for elimination and are being (or have already been) removed:
- 51st Street
- Techni Center Drive
- Bolm Road
- Vargas Road
- Thompson Lane
As 183 South was developed, traffic engineers identified the major cross streets with the greatest current and projected traffic volumes. Priority was placed on maintaining those crossings. As designed, cross street intersections and turnarounds will be spaced roughly every mile. This spacing improves mobility and enhances safety by reducing the number of signalized intersections on the general-purpose lanes. It also allows for entrance and exit ramps to be located further away from cross streets, allowing them to function more efficiently.
Based on feedback from residents, and in order to improve mobility, a number of turnarounds or Texas U-turns are added to facilitate connectivity and the movement of local traffic. The Texas U-turns are located at Loyola Lane, Martin Luther King Boulevard, near Harold Court, and at Montopolis Drive. These non-signalized Texas U-turns, in most cases, allow drivers to reach the other side of the new expressway at least as fast as they did prior to construction, and in many cases, even faster.
By removing the five existing signalized cross streets and incorporating non-signalized U-turns, travel times are comparable, and in some cases faster, than prior to construction despite added travel distance, all due to greater overall mobility throughout the entire corridor.
For more information, please download a presentation on this subject that was provided to the Mobility Authority Board of Directors in June 2016.
For specifics on each cross street removal, please see the following:
A 51st Street overpass was considered in response to public input. However, an interchange was not added because it did not meet project criteria. Traffic volumes using the crossover were lower than adjacent cross streets, as 51st Street does not continue east of US 183. The roadway design was coordinated with the YMCA and with adjacent neighborhoods; and as a result, a pedestrian bridge was added at 51st Street, as well as, a deceleration lane for drivers turning onto 51st Street from the non-tolled general purpose lanes and an acceleration lane for drivers entering the general purpose lanes from 51st Street.
There are now non-signalized u-turns at the nearby intersections of MLK Boulevard and Loyola Lane to provide drivers easy access to and from 51st Street.
The crossing at Technicenter Drive was removed because it did not meet project criteria. Technicenter is a low volume roadway that becomes a private road on the east side of US 183. Traffic data and engineering analysis determined that improved operations would be achieved by not providing a crossing at this location. And in order to optimize connectivity in this area, a turnaround was added near Boggy Creek.
There are non-signalized U-turns at the nearby intersections of MLK Boulevard and near Harold Court to provide drivers easy access to and from Technicenter Drive.
Prior to construction, the US 183 mainlanes crossed Bolm Road with an overpass. The early design of the project incorporated an overpass for Bolm Road with a proposal for collector-distributor, or bypass, ramps to accommodate both tolled and non-tolled access.
However, it was recommended for removal when a Federal Highway Administration (FHWA) Value Engineering Study identified the complexity of the braided collector-distributor ramp system as a major safety concern due to the high number of conflict points and potential for collisions. The final decision to remove the proposed crossing at Bolm Road considered FHWA Value Engineering Study results and public feedback and was based on safety, traffic operations, the negative impacts of elevated collector-distributor structures, and cost.
There are non-signalized U-turns at the nearby intersections of Levander Loop and near Harold Court to provide drivers with easy access to and from neighborhoods and businesses near Bolm Road.
Both locations were considered for crossing access, but did not meet criteria for inclusion in the design based on operational issues and traffic volume analysis.
However, during the environmental study phase, public concern was raised about not providing a crossing at Vargas Road. To address that concern the design team looked at opportunities to provide a crossing in that area. Vargas was ruled out due to its close proximity to the Montopolis Drive crossing. Vargas Drive was also in close proximity to a number of large historic oak trees that are designated for preservation. Because the design team committed to preserve as many of the large oak trees as possible, engineers found that it was not possible to construct a crossing at Vargas Road or Thompson Lane. Instead they found a suitable location at Patton Avenue.
There are non-signalized u-turns at the nearby intersections of Patton Drive & Montopolis Drive to provide drivers easy access to and from Vargas Road or Thompson Lane.
The Texas Department of Transportation conducted an Environmental Assessment for the project between 2011 and 2015. In accordance with federal and state requirements a robust community outreach effort was undertaken with numerous opportunities for public input. All stakeholder input was considered within the context of the entire region’s mobility needs and a number of design changes were made based on public input, when it was reasonable and feasible to do so.