Growing Separately, Together

As the population goes, so does the road. The combination of transportation planning, design and construction is a multi-billion dollar enterprise that grows concurrently with a rise in population.

Nevada, Arizona and Colorado are examples of states whose population is rapidly increasing and, coincidentally, are home to some of the nation’s largest road redesign and construction projects.

According to the U.S. Census Bureau, the three fastest growing states in the U.S. are Nevada, which showed the fastest growth since Census 2000 at a rate of 5.4% per year; followed by Arizona, which grew at a rate of 3.4%; and Colorado at 2.7%. All three states grew faster than the nation as a whole, which grew overall by 1.2%

As a result of the population growth, Nevada is currently involved in major transportation projects with a cumulative total cost of $3 billion; Arizona is currently constructing projects valued in the neighborhood of $650 million; and Colorado is constructing projects assessed in the area of $2 billion.

In order to better understand this relationship, Transportation Management + Engineering examines the correlation between population growth and traffic planning in the states of Nevada, Arizona and Colorado.

Aggregate view

Common parallels follow the trends of population growth. As the number of inhabitants in a certain area increases, traffic congestion tends to increase along with travel times. The need for the redesign of current roads and new road construction to resolve the problem of congestion as it relates to population growth has become increas- ingly important.

Each of the three states, Nevada, Arizona and Colorado, and their respective departments of transportation are involved in multi-faceted road construction projects—two alone have a total cost that runs into the billions.

Nevada, which has been the fastest growing state for the past 15 years, is in the midst of constructing the new Las Vegas Beltway, a $1.5 billion, 53-mile roadway that incorporates an accelerated beltway design and is scheduled for completion in 2018.

Arizona is currently involved in a number of redesign projects, which will add approximately 40 miles in and around Phoenix. In 2001 alone, 20 miles of new roads were opened in the area with the largest of these projects being the Superstition Freeway, a three-lane project in Phoenix.

Finally, Colorado has broken ground on the $1.7 billion Transportation Expansion Project (T-REX) for Denver’s Southeast Corridor, a redesign project which includes highway expansion and improvements on I-25 and I-255 as well as a light rail transit system.

Nevada

Throughout the past two decades, the state of Nevada, and specifically Clark, County, Nev., has been identified as one of the fastest growing regions in the U.S. Last year, Nevada and Clark County continued to break national growth rec-ords, according to the U.S. Census Bureau.

Clark County is home to one of the nation’s major transportation projects, the $1.5 billion Las Vegas Beltway.

Started in 1993, the Beltway is divided into segments one to two miles in length. According to the Nevada DOT, the goal is to complete 18 separate projects, which will encompass approximately 20 miles, by 2003. The entire job is scheduled for completion by 2018 and will result in a total of 53 miles.

Due to the increase in population in southern Nevada, local officials re-designed the original plans for the Beltway and pushed for the “accelerated” design and construction plan in order to get the project completed as quickly as possible.

According to the Clark County Department of Public Works, “The Las Vegas Beltway is being constructed in an effort to help support the travel demands of a rapidly growing community and is intended to reduce urban congestion, improve overall traffic capacity and enhance area-wide air quality.”

Existing transportation needs throughout the state of Nevada are reflected in the Beltway project. In areas where there is heavy traffic volume, a full or partial freeway will be constructed. In areas which contain light development and vehicle flow, multi-lane arterials will be built with a design that incorporates the future—the Beltway may have as many as 10 lanes in each direction if population continues to boom and the extra transportation is needed.

Other projects in the state reflect the transportation needs of a swelling population. Projects include work on U.S. 95 in Northwest Las Vegas ($510 million); I-580/U.S. 395 freeway extension to the state capital ($250 million); U.S. 93 Hoover Dam bypass ($200 million); U.S. 93 through Boulder City ($170 million); U.S. 395 Carson City bypass ($160 million); and the widening of I-15 from Las Vegas to the California state line ($100 million).

The U.S. 95 project serves the growing transportation needs of the Northwest Region of the Las Vegas Valley. According to NDOT, the U.S. 95 redesign and construction was undertaken to relieve current congestion as well as accommodate the continued growth of the community.

Arizona

The problem of congestion in the state of Arizona can be attributed to an average area decade growth rate of 42%, according to the U.S. Census Bureau.

In 2001, 20 miles of new freeways were opened in the Phoenix area with even more opening annually until 2007. These projects, with an aggregate total cost in the neighborhood of $650 million, are a result of the population boom that is evident in the Phoenix area.

Projects in Arizona include the Superstition Freeway (U.S. 60) widening between I-10 and Val Vista Drive ($270 million); Pima Freeway-Shea Boulevard and Princess Drive ($80 million); Pima Freeway-19th Avenue and Scottsdale Road/Scottsdale Road and Princess Drive ($80 million); Price Freeway-Guadalupe and Warner Road ($65 million); Red Mountain Freeway-Gilbert Road and Higley Road ($65 million); Red Mountain Freeway-Country Club Drive and Gilbert Road ($56 million); and I-10 Freeway interchange ($26 million).

With the exception of the Superstition Freeway, all projects entail a three-lane construction plan. The Superstition Freeway is primarily a redesign project with contractors also adding two general-purpose lanes, an HOV lane and some auxiliary lanes to the existing three-lane road.

The Arizona DOT cited a growing population in the Phoenix area as its reason behind the Superstition Freeway project. “As population in the East Valley [Phoenix] continues to grow, roadway traffic increases and our roadways become more congested. Without improvements, congestion along the Superstition Free-way will continue to in-crease. Traffic demand on the Superstition Freeway is forecasted to increase as much as 20% over the next 20 years.”

Colorado

Currently, 28 projects make up the state of Colorado’s Strategic Transportation Project Investment Program. Nineteen of these projects are primarily mobility improvements. Examples of the program include the I-25 Corridor which extends north between Denver and Fort Collins and south through Colorado Springs and the T-REX project. Other projects include Powers Boulevard in Colorado Springs; U.S. 285 from Jefferson County in the Denver metro area; U.S. 160 and SH 550 in the Durango area in southwestern Colorado; and SH 82 from Basalt to Aspen on Colorado’s western slope.

“These type of projects generally relate to the higher growth areas within Colorado,” said Marilyn Beem, statewide and regional planner for CDOT.

Although Colorado’s population increased by 48% between 1980 and 2000, vehicle miles of travel on Colorado’s state highway system increased by 89% over the same time period.

“That high rate of growth in the use of the state highway system is having a significant impact not only for congestion and other mobility-related issues, but also for the state’s ability to maintain its infrastructure,” said Beem. “These strategic projects are located in corridors with high growth in traffic.”

At the forefront of these projects is the marriage between I-25 and I-255, known as T-REX.

Profiled in the October/November issue of Transportation Management + Engineering (see Designs Reflect Traffic Growth), T-REX was redesigned as a result of large population growth and large business migration to the south Denver area. Originally built to handle 180,000 vehicles, the corridor currently sees traffic volumes upwards of 230,000 on a daily basis.

According to the Colorado DOT, the main factors that defined the T-REX project were the existing severe congestion throughout most of the corridor, the high accident rate in the northern part of the corridor, the deficiencies in the existing transit service and the growing population and employment in the corridor.

Extra highway lanes, as well as a light rail system, were incorporated into design plans as a measure to help ease congestion in the area, at least enough that the current traffic situation will not worsen.

“Particularly in the urban areas, demand far exceeds available capacity,” said Beem, “and in many cases there are financial, environmental, social or other constraints to adding sufficient road capacity to accommodate forecast volumes. In these corridors (such as T-REX), we are looking to partner with the local transit agencies to cooperatively develop multi-modal projects.”

Prior to construction of the T-REX project, Colorado Sen. Wayne Allard said, “This multi-modal project is an important step towards addressing the transportation needs of Colorado’s rapidly growing population.”

The population in the Denver area has nearly doubled in the past 20 years with trends and projections showing this growth will continue to increase. Currently, Denver’s population is approximately 2 million people. By 2015, the metropolitan Denver area population is estimated to be 2.5 million, not including the Aurora area south of Denver, which is expected to reach 400,000.     TME