This study investigated whether highways acted as barriers to gene flow for pronghorn in northern Arizona. DNA samples from 132 pronghorn were analyzed using eight polymorphic microsatellite loci. Samples represented animals living on opposite sides of US Route 89 (US 89) and State Route 64 (SR 64). Two different modeling approaches indicated that both US 89 and SR 64, and to a lesser extent US Route 180 (US 180), acted as barriers to gene flow. The genetic structuring caused by highways, especially across US 89, is consistent with behavioral data that demonstrated pronghorn rarely cross this highway. This study found no evidence of inbreeding or reduced genetic variation in any of the populations examined, but those effects may take longer to appear. Based on these results, the researchers recommend future genetic monitoring of these populations or assessment of genetic variation across highways with larger traffic volumes or longer histories to determine whether the barrier effects documented here lead to loss of genetic diversity.

The Arizona transportation history project was conceived in anticipation of Arizona’s centennial, which will be celebrated in 2012. Following approval of the Arizona Centennial Plan in 2007, the Arizona Department of Transportation recognized that the centennial celebration would present an opportunity to inform Arizonans of the crucial role that transportation has played in the growth and development of the state.

The report consists of a historical narrative and a series of topical essays. The seven-chapter historical narrative is a history of Arizona’s highways that extends from the pre-Columbian era to the present. The 14 topical essays extend the scope of the history beyond the state’s highway system. They include overviews of the development of other transportation modes (railroads, aviation, and urban transit), a brief history of highway pavements, a lighthearted look at the motoring experience during the 1920s and 1930s, and an exploration of how changes in transportation infrastructure affected some Arizona communities. The topical essays also provide additional historical information on bridges, urban freeways, the Interstate system, ADOT and its predecessor agencies, and famous roads such as U.S. Route 66, U.S. Route 89, the Black Canyon Highway, and the Beeline Highway.

The report also includes a timeline of transportation-related developments. This chronology not only provides an accessible overview of Arizona’s transportation history; it also places that history in a larger context by including transportation-related developments from the rest of the nation and around the world. Finally, the report contains a guide to archives in Arizona that hold significant collections of historical photographs related to the state’s transportation history, a bibliography of published historical sources related to the history of highways in Arizona, and a discussion of how the historical narrative and topical essays could be used to produce publications and media that would be made available to the public.

The purpose of this document is to provide guidance and detail on implementation of the Flood Control District of Maricopa County Floodplain Regulations and the Maricopa County Drainage Regulations. It presents the County/District philosophy on drainage and floodplain management, and planning for drainage facilities. It contains descriptions of federal, state and county regulations pertaining to such facilities, including links to the various District and County regulations that can be found on the Internet. Most importantly, the policies and minimum standards for implementing the regulations are presented. These policies and standards are based on flood and erosion hazard mitigation strategies that are intended to reduce or eliminate cumulative impacts resulting from development and to enhance public safety.

Some freeway users complain that new freeway segments fill up with traffic during peak hours immediately after construction. Because of this concern, the debate about the costs and benefits of freeways often centers on relieving congestion. The literature states that the long-term relief of congestion is an elusive goal. While congestion is a pervasive feature of freeways, it does not mean that constructing them is useless. This study helps to demonstrate that the great benefit of freeways is to facilitate travel rather than reduce peak-hour congestion. The study finds that the facilitated travel far outweighs the cost of freeway construction. Even if new freeway capacity becomes congested during peak travel hours, there is still great benefit in the increased travel mobility that can be accommodated.

The 2009 Comprehensive Floodplain Management Plan and Program is intended to be used as a general guide for future decision-making in District activities. The Plan aims to present adequate background information to aid District staff in prioritizing areas for future studies and projects. The Plan identifies historic flooding events, reviews the District's efforts to solve flooding problems, and formulates five-year plans to reduce flooding through flood control project construction, floodplain identification, and planning programs throughout the county.

Approximately 11,000 miles of rivers, streams and washes run through Maricopa County. In order to enhance and maintain the benefits provided by these watercourses, the Flood Control District of Maricopa County engaged in an effort to refine its role in river planning and management. To develop an enhanced river planning and management strategy, District staff adopted a process called C3RPM. The core C3 process addresses complex issues with a blend of comprehensive information collection to solicit diverse opinions; a coordinated and deliberative assessment of that information; and a collaborative decision-making system free of bias to promote a consensus result.

The District's Coordinated, Comprehensive, Collaborative Flood Hazard Mitigation Partnering (C3FHMP) effort addressed Strategic Initiative No.3 of the Flood Control District of Maricopa County 2009 Comprehensive Plan: Increase Collaboration and Partnerships. The District initiated the process to determine how the funding and resources of other entities could be best applied to mitigate flood hazards in Maricopa County, or where mutual benefits would be realized.