As part of a major multi-phase U.S. 95 Northwest corridor improvements project, work is currently underway on a new system to system interchange between U.S. 95 and Clark County (CC) 215 Beltway.  

According the Nevada Department of Transportation (NDOT) the overall project will improve U.S. 95 from Washington Avenue to Kyle Canyon Road in northwestern Las Vegas. The U.S. 95 NW Project will add lanes on U.S. 95; construct Skye Canyon Park Drive (formerly Horse Drive) and Kyle Canyon Road interchanges; and the system-to-system interchange. The project will also add auxiliary lanes, ramp metering and landscape and aesthetic improvements.

The current phase of the project is a $47 million contract that includes construction of that new interchange, dubbed the "Centennial Bowl."  Las Vegas Paving is the lead contractor on the work, Phase 3A of the overall project, which began construction late last year and is slated for completion in 2017.

Creating Better Connectivity

The elements of the project include construction of connection ramps from north and southbound I-95 to east and westbound 215 respectively.  The ramp from southbound I-95 to westbound 215 will cross over two major freeways to make that line.  The flyover bridge will be 60-foot-high, and 2,500-feet-long. A collector distributor road for southbound I-95 will be added. Approximately 5,500 linear feet of reinforced concrete box storm drain will be installed.   Additionally, tie back walls will be built at the Ann Road structure along westbound CC 215 will be built. There will also be new lighting, signs and landscaping.

Clark County Commissioner Larry Brown sees the project as enhancing the cultural and economic access to the northwest Valley.  "It establishes a new gateway corridor for the Centennial area," said Brown.

Another benefit of the project will be the economic lift resulting from the project 600 plus direct, indirect and induced jobs related to the construction.

According to the Regional Transportation Commission of Southern Nevada, "This first phase of the proposed system to system interchange will construct two direct access ramps easing congestion and enhancing safety on the local streets and throughout the interchange."  It is an important benefit, as traffic on the ramps and beltway is currently 107, 500 vehicles per day, and projections show this could increase to 160,000 vehicles per day over the next 20 years. 

A few months into work on the project, and contractors have made solid progress, but it will be quite an effort to get the project completed on time, with night work expected, according to project managers, and a few "weekend marathons."

Motorists will need to take detours during various stages of the project and there will be temporary shutdowns. Communications with the public are ongoing to ensure that motorists are aware of the changes, take alternative routes when possible, and proceed with caution through the work zone.

Securing Funding

Funding for the current project comes from several sources. The Federal Highway Administration provided $19.5 million.  There is also $14.4 million from the Clark County Regional Flood Control District. The State of Nevada provided $6.4 million, with an additional $6.4 million financed through the regional Fuel Revenue Indexing program (FRI).

Fuel Revenue Indexing takes some of the fuel tax motorists pay at the pump and funds needed road maintenance and improvements. What makes the FRI mechanism most useful to transportation planners is that it ties the fuel tax to the rate of inflation to provide critically needed funds for transportation infrastructure projects. Unlike a sales tax, which is a percentage of the total price of an item, the fuel tax is currently a fixed amount per gallon.

While fuel tax rates have not been adjusted in 17 years, the cost of building streets and highways has increased significantly just like the prices of other goods and services. In other words, new roads may cost 2013 prices, but the fuel tax was being collected based on the prices of 1996. Thus, the intent of fuel revenue indexing is to enable the taxes paid at the pump to better support the current costs of transportation projects.

Under legislation passed by the Nevada legislature, the Clark County Board of Commissioners passed an ordinance on September 3, 2013, that ties the fuel tax in Clark County to an inflationary index (Producer Price Index) from January 1, 2014, through December 31, 2016. The fuel revenue indexing will generate $700 to $800 million in bonding capacity, enough to fund 220 significant transportation projects throughout Southern Nevada and create over 9,000 jobs.  According to officials, this reliable source of funding costs residents an average of about 10 cents per day.  At least eight other states, including California and Wyoming, have raised fuel tax rates, taking an approach similar to Fuel Revenue Indexing.

Completing Tie-Back Walls

Abid Sulahria, Project Engineer with NDOT, said that after just a few weeks of work, crews had completed ground excavation, and abutments, and had finished the tie-back walls. 

Chris Garamendi, P.E., from Las Vegas Paving, explained that the tie-back wall "is the same concept as a soil nail wall only the tendons are post tensioned after they are installed and grouted." Soil nailing is a method of slope stabilization involving the installation of closely spaced earth anchors. Soil nail walls take advantage of grout-to-earth friction to create a self-supporting earth mass.

Garamendi also noted that much of the work on the bridge pier construction has been done, with nine of 10 drilled shafts for the CIDH piers completed. Subcontractor Hayward Baker, using a Soilmec SR 100 Hydraulic Drilling Rig, dug the 10-foot-diameter shafts, each 60- to 80-feet-deep.

Sulahria said a unique feature of the project is the extensive flyover bridge and the double-decker falsework that will be required to construct that bridge.