Houston, Texas is seeing fast expansion of population, with in vast increases in traffic
First publishedin World Highways
The new road layout will allow for the city's expected population growth - image courtesy of Trey Cambern, HNTB
The US city of Houston is expanding fast and its transport system is having to be developed to cope – Mike Woof writes
Located in Southeast Texas, Houston is currently the fourth most populous city in the US overall while it has the largest population of any city in the Southern United States. The census for 2017 estimated that Houston is home to 2.3 million inhabitants and there is a huge expansion in the number of people living in the area. For the period from 2010 to 2040, it is estimated that the population will grow some 72% in the Houston region.
With so much of the city’s transport relying on its road network, it is understandable that the existing system is already becoming clogged. Congestion is common at peak travel times, resulting in traffic delays and extended journeys. Clearly, there is a requirement to boost capacity along some of Houston’s important roads and highways, and some parts of the city have a particularly pressing need. With an eye to the future, the Texas Department of Transportation (TxDOT) has been busy planning a series of major road upgrades and widening projects to help deliver the necessary transportation capacity.
Two massive road construction projects being handled by TxDOT are of particular importance for freeing up traffic flow in the city.
One is for the Grand Parkway (SH 99) project which, by 2022, will become the biggest highway loop in the US and has an estimated cost of US$1.28 billion. The project extends from the existing sections of the SH 99 route and when complete the Grand Parkway will run for 294km around the city. The first stretch of SH 99, Segment D, was opened in 1994 with the most recent stretch, Segment G, opening in March 2016.
According to TxDOT, building new highway lanes and upgrading the tolling technology used at present will provide the capacity need. The first 84km section of the route should be complete by the second quarter of 2022. This will run from New Caney to the north-east of Houston’s centre to Baytown, located to the east.
Construction of this section, which comprises the H, I-1 and I-2 stretches, is being carried out by a partnership comprising Ferrovial Agroman Construction, Granite Construction and Webber, with the contract worth $855 million. In all, preparing the site includes shifting 708,000m3 of earth, while in addition to building new road lanes the construction work will require building 74 bridges.
Construction ensures that site personnel have safe working areas - image courtesy of Trey Cambern, HNTB
Meanwhile the other major project is for the reconstruction of a 61km section of the US 290 highway, which runs between the central I-610 loop in the city and the north-west of Houston. The US 290 Corridor stretching from I-610 to the Harris/Waller County line has been identified as one of Houston’s key areas for urban growth and its population is expected to jump from around 700,000 at present to 1.1 million by 2040. This corridor to the north-west of Houston from the interchange between US 290 and I-610 as well as the nearby interchange (just to the south) between I-10 and I-610.
The original US 290 Programme drawn up involved improving capacity on US 290 as well as building the parallel Hempstead Tollway. And in August 2010 the US Federal Highway Administration
(FHWA) gave its go-ahead when it approved the programme's Final Environmental Impact Statement (FEIS), which included the plan to build the extension to US 290 and also construct the Hempstead Tollway.
However, there were concerns that the planned layout would not provide as efficient a traffic flow as intended and also that the cost would be comparatively high. With limitations in the financing available, TxDOT took the sensible step of revising its initial plans in the knowledge that some of the features of the original US 290 Programme would not feasible in the short term. But understanding the pressing need to meet the challenges posed by the growing population in the area, TxDOT has opted to introduce as many improvements to the US 290 route as possible while achieving the best value from the budget available.
Geotechnical consultants carried out studies of the entire US 290 Corridor as part of the design process. The bridges, storm sewers, retaining walls and detention ponds were designed with consideration of the silt, sand and clay soil found along the Texas Gulf Coast.
A geotechnical challenge faced was the existence of the Brittmoore Fault, which crosses US 290 approximately 13km from the program’s eastern limit, near the US 290 and Beltway 8 interchange. In the area of the fault, care was taken to avoid building structures that would be sensitive to movement.
Design surfaces were created with Inroads SS2 from Bentley software, and used in conjunction with Trimble Business Center and Topcon 3D software to create survey files for Trimble data collector and machine control files for Trimble and Topcon machine control systems.
Construction has been underway for some time as drivers around Houston will no doubt be aware. Work started on the US 290 upgrade in 2011 at the junction with I-610. Building of five of the sections is now more or less complete while construction activity is underway on a further eight sections.
The construction operation is optimised to limit traffic restrictions
TxDot says that safety is its top priority, and one of the biggest challenges on a large-sized program like US 290 is keeping traffic moving safely through areas where crews are working. All 13 programme projects have detailed Traffic Control Plans (TCP) spelling out how motorists are detoured through construction areas.
According to TxDOT, “Traffic was managed very similarly on all of our segments. A combination of temporary pavement widenings and reducing the number of travel lanes each direction as well as the individual lane widths. This allowed us to shift traffic away from our work areas to allow for the new roadway construction.”
Protecting the public as well as construction workers was the top priority during three major flooding events that occurred during US 290 Program construction.
In addition to carrying out work on the Grand Parkway project, Houston-based Webber is also the contractor handling the earthmoving and road paving portion of Segment 5 for the US 290 project.
Worth $172.2 million, the Segment 5 portion of the project involves reconstructing approximately 5.6km of the US 290 main lanes as well as the frontage roads in Harris County. This work commenced in November 2015 and should be finally completed by April 2019. The work includes rebuilding Highway US 290 in Houston, between east of W Little York and the west of Pinemont. The change to this section of US 290 has involved transforming the seven lanes into a layout with six travel lanes and one auxiliary lane in each direction. It has also included rebuilt, two-lane frontage roads.
In 2016, Webber completed a key stage of its activity on the Segment 5 portion of the US 290 project. The company says its successfully completed the switch of the WB mainlines over new pavement from Fairbanks up to W Little York. In addition, the firm also opened two new permanent ramps to traffic.
Using the right tools for a job helps with project delivery and to ensure that Webber carries out its operations efficiently, the firm has invested in some of the latest machine control technology, supplied through the local SITECH outlet Southeast Texas. These are the Trimble Business Center -HCE package, GCS900 Grade Control System, SCS900 Site Controller Software, SPS930 Universal Total Stations and Trimble TSC3 Controller .
The company used the Trimble SCS900 Site Controller Software to set control, layout and grade check the entire project. The firm then used Business Center - HCE software to build the project model, which was exported in various formats for use on its Trimble GCS900 Grade Control System. The planer operators used the GCS900 Grade Control System to automatically control the drum cutting depth to design grade, which helped to reduce the number of passes required. Optimising the milling process also reduced the need for additional preparation work.
The I-610 US 290 interchange will carry some of the heaviest traffic loads
In addition, machine operators from Webber used the Trimble GCS900 Grade Control System on a grader along with the Trimble SPS930 Universal Total Station. This set-up helped provide the precise vertical guidance so that the contractor could deliver the precise grading required more quickly and more accurately. The system achieved this by measuring the lift, tilt and cross-slope of the blade, and by providing the operator with in-cab elevation and slope guidance.
“We use technology on all of our jobs, and especially larger projects like this one,” said Mauro Lopez, survey manager at Webber. “We use grade control for all of our fine grading, and we’re always exploring new ways we can use the capabilities in Business Center - HCE. In fact, we have recently added more than 10 subscriptions to Business Center - HCE for our field and office workers. On this job, we relied on the transformation tool in Business Center - HCE, which allows us to use adjusted data for things like detours and heavy duty modelling.”
The new layout has been constructed with improved connector ramp designs that help to improve traffic flow and reduce the risk of crashes. These ramps provide a better flow of vehicles between US 290, I-610 and I-10, a section of the network that carries particularly heavy traffic flows at peak periods. This new design ensures that vehicles can enter and exit US 290, I-610 and I-10 without causing disruption to other traffic. The revised layout has been designed to help tackle congestion points occurring during the usual rush hour periods.
The overall vision for the US 290 Programme is extensive, with the key feature being the reconstruction of the route to boost its capacity and this involves widening the highway, extending from I-610 to the north-west. This work will deliver five/six general-purpose lanes in each direction from I-610 to just west of SH 6, as well as auxiliary lanes where appropriate. The project will feature four general purpose lanes in each direction from just west of SH 6 to near the coming SH 99/Grand Parkway project, as well as auxiliary lanes. It will also feature three general purpose lanes in each direction from near the proposed SH 99/Grand Parkway to the west study limit, as well as auxiliary lanes. And it will benefit from two- or three-lane frontage roads in each direction throughout the corridor.
Key Participants in US 290
Owner - Texas Department of Transportation – Houston District
PROGRAM MANAGEMENT CONSULTANT HNTB
PRIME CONTRACTOR FOR PROJECTS A, B, C1, C2, D, E, J1, J2 AND K - Williams Brothers Construction Company, Inc – Houston, Texas
PRIME CONTRACTOR FOR PROJECTS F, G AND H - Webber, LLC – Houston, Texas
PRIME CONTRACTOR FOR PROJECT I - OHL, USA, Austin, Texas
The construction team has faced numerous challenges during the project
TxDOT said, “Before work began on the project, our survey crews first verified all of the control points and made sure all of the data tied together. We then laid out the ROW to establish our project limits and provide a reference for any utility companies that needed to start their relocations. Special consideration was given to the Segment 5 project since it was taken over from another contractor and some of the work had already been completed. It was discovered that there were some alignment and elevation issues. To resolve these issues our surveyors and engineering services department modified the overall profile of the project to fit what had been previously been constructed. Once construction started the surveying needs were approached like most projects. A surveyor manager coordinated the survey crews in the field. Our highest survey demands were on the Segment 5 project, which required up to three crews in the field.”
As well as optimising the design, the project team has also incorporated some of the latest road construction methods. At US 290 public meetings, residents expressed concern about noise from the roadway. To mitigate noise, the team worked with the TxDOT Maintenance Division, researchers from the University of Texas at San Antonio, and the International Grinding and Grooving Association (IGGA). TxDOT chose to incorporate on the US 290 project a pavement noise reduction technique called Next Generation Concrete Surface, which had not previously been used in Texas.
According to the IGGA, upward protruding pavement textures create much of the tyre-pavement noise. The contractor places longitudinal grooves on the concrete to minimise those textures. The Next Generation Concrete Surface provides a long-lasting surface texture that decreases tyre and pavement noise. Special equipment and crews are working with contractors to apply the technique in every segment of the project, at an estimated cost of $17.7 million.
The ACPA claims that the NGCS is the quietest non-porous concrete texture developed to date. At the time of construction, the NGCS will result in a noise level of around 99dBA and will have a typical range up to 102dBA over time according to the ACPA.
The NGCS surface was developed in a partnership between the International Grinding and Grooving Association (IGGA), ACPA, Portland Cement Association and Purdue University. Extensive field testing was conducted by the Minnesota Department of Transportation (MnDOT) at the MnROAD low volume road test track.