August 4, 2007
Cascabel Working Group
6590 N. Cascabel Road
Benson, AZ 85602
Dear Cascabel Working Group:
You have my permission to publicly display or distribute the following text that I sent 1 August 2007 to the members of the Technical Advisory Committee and State Transportation Board of the Arizona Department of Transportation:
As a clarification of, and in addition to, what I stated on the I-10 Phoenix/Tucson Bypass Study Comment Form, please consider my thoughts about each of ADOTs four purposes of a bypass (quoted from http://tpd.azdot.gov/planning/i10bypass.php).
1. Provide an alternative route to I-10 to relieve traffic congestion in the Tucson and Phoenix metropolitan areas.
Because of the enormous financial, environmental, and social costs involved, bypass routes that cant significantly reduce congestion in both cities should not be considered. ADOTs Existing Traffic Volumes (2005) map shows I-10 traffic within Tucson and Phoenix (137,000 and 297,000 vehicles per day, respectively) to be far greater than the I-10 thru traffic (13,000 vehicles per day; best indicated by the traffic volume east of Bowie). Bypasses that wont closely circumvent these congested urban segments, such as the bypass proposed along the San Pedro, wont be effective. Even if half of the I-10 thru traffic used a San Pedro bypass, Tucsons congestion would decrease by less than 5% (13,000 ÷ 2 ÷ 137,000 X 100% = 4.7%), and that of Phoenix by less than 3% (13,000 ÷ 2 ÷ 297,000 X 100% = 2.2%). Although these calculations are based on 2005 measurements, I would expect the ratio of thru traffic to urban traffic to remain the same or decrease for 2007, 2008, and so on. Therefore, calculations using current or future measurements should show reductions in Tucson and Phoenix congestion that are similar, or even less, than those calculated using the 2005 numbers.
To clarify my reasoning above, the volume east of Bowie (13,000 vehicles per day) includes approximately all of the drivers who would choose to take a San Pedro bypass. Of course, this volume also includes drivers who would not choose to take a San Pedro bypass (e.g., Tucson residents and visitors, truckers with a Tucson or Mexico origin or destination). For my calculations, I liberally assumed that half (13,000 ÷ 2) of the drivers would choose a San Pedro bypass. The greater traffic volumes west of Bowie (14,000; 15,000; and 30,000) probably dont indicate a significant number of additional drivers who would choose to take a San Pedro bypass, since almost all of this additional traffic volume is probably comprised of drivers traveling between southern Arizona locations (e.g., Tucson - Sierra Vista).
2. Provide a shorter, faster east-west route through Arizona that would attract through-trucks and other traffic from I-10.
I have four thoughts about this purpose: 1) Businesses and attractions (truck terminals, Rio Nuevo, etc.) along I-10 want to attract I-10 traffic. 2) Truckers wont be attracted to a route having more curves and hills. 3) There are a great many projects that are far more deserving of Arizonans transportation dollars than a route to get non-residents through our state more quickly. 4) The treasured areas for which Arizona is renowned and loved should not serve as shortcuts for those just passing through.
3. Provide a new route that offers an alternative path for I-10 traffic during construction, maintenance and incidents.
An alternative path is useful only if it closely circumvents the segment of construction, maintenance, or incident. The most congested urban segments of I-10 have the highest probability for incidents and severe traffic disruption. Bypasses far removed from these segments, such as the bypass proposed along the San Pedro, wont be useful.
4. Provide a new east-west transportation corridor in Arizona to serve the expected rapid population growth and land development.
The purpose of any new route should be to facilitate transportation, not development. The route should be justified by proven need (e.g., actual traffic volumes), not speculative prophecy (e.g., traffic forecasts and population projections, which cant account for many important growth-related factors such as drought, water sources, Central Arizona Project allocations, air quality, climate change, energy costs, war, immigration reform, housing market, national debt, education, healthcare, state trust land initiatives, and the loss of Phoenix semiconductor and high-tech manufacturing to overseas facilities).