Staying Connected

Direct Connect Interchanges are vital to every municipality and freeway system because they are the single largest mover of traffic. To put that into perspective, almost 600,000 vehicles go through the IH 610 West Loop/IH 69 interchange in Houston every day. If for any reason they fail to work, traffic is adversely affected across an entire region.

LJA’s Transportation Sector has completed or is currently working on 14 Direct Connect (DC) Interchanges across Texas.

Direct Connect Interchanges consist of the most complex roadway, traffic control, drainage, and structural situations we face as Transportation engineers. For this reason, it is critical that our experience and expertise is perfectly delivered on every challenge when designing these projects.

Interchange designs are a result of many factors—such as different bridge support structures and utilities needing to be placed on limited available real estate and land while the structures are being built. These restrictions result in long spans and special geometrical shapes. Extensive coordination is required from both an engineering and agency standpoint, but also a public and elected official perspective. Ideally, these interchanges need to be reconstructed without traffic interruptions while still guaranteeing the safety of the traveling public. Additionally, they are also the most expensive roadway segments, costing upwards of $300M for a single location.

IH 610 NB to IH 69 SB Direct Connector
As part of the overall interchange reconstruction from IH 610 Northbound to IH 69 Southbound, the project realigned the southbound IH 69 frontage road, and included retaining walls, sound walls, and pump stations. It consisted of long curved trapezoidal box beams and large diameter single shaft foundations, complicated traffic control, and regional detention upgrades to improve drainage throughout the area and improve safety at a previously deadly location.

Tomball Tollway (SH 249)/SH 99 Direct Connect Interchange
LJA provided bridge design for four new direct connectors including northbound/eastbound (NB/EB), northbound/westbound (NB/WB), westbound/southbound (WB/SB) and eastbound/southbound (EB/SB). This was the first use of curved concrete spliced girders in the state of Texas.

Hardy Toll Road/SH 99 Seg G Direct Connect Interchange
LJA provided SCH and PS&E for four direct connectors, plus the widening of Riley Fuzzel overpass and sound walls at Dennis Johnston Park. LJA completed the plans in only seven months.

IH 35 Direct Connector from IH 35 SB to IH 410 SB
The project improved mobility, operations, and safety of the interchange, including revising the existing ramp configurations on IH 35 in the proximity to the interchange. The greatest design accomplishment was converting a left exit from IH35 to IH410 to a right hand exit.

IH 10 Connect
LJA provided PS&E for proposed improvements at the IH 10/IH 110/US 54/US 62 interchange, consisting of additional direct connectors and ramps to improve mobility in the downtown El Paso area. LJA was responsible for illumination, landscape and aesthetics design, and bridge design for nine direct connects and mainlane bridges. LJA worked thoughtfully to design aesthetics that maintained the integrity of the adjacent neighborhood and historic Lincoln Park.

SH 99 Seg E Grand Parkway/US 290 Interchange
LJA provided PS&E for two direct connectors using long span curved steel plate girders and large diameter monoshaft foundations. It currently passes over UPRR/US 290, however, the interchange was designed to be depressed under the UPRR in the future.

LP 1604 SB to US 90 EB Direct Connector
As a part of the reconstruction from US 90 to Potranco, LJA provided SCH and PS&E to expand a 4-lane expressway, which included a southbound-to-eastbound direct connect. We also planned for future interchange and freeway improvements. Unique lighting was installed to minimize effect on nighttime military training operations at nearby Lackland Air Force Base.

Hardy BW 8
LJA provided program management, SCH, and PS&E for the design of new direct connect interchanges related to refining and developing the final design of the Hardy Toll Road (HTR) at Sam Houston Parkway (SHP) interchange.

Contact Todd Thurber, PE, Senior Vice President for more information.