An update to the Flagstaff Regional Plan 2030 (FRP30), to bring its Road Network Illustration (Map 25) into compliance with Arizona Revised Statute requirements and to resolve inconsistencies between Map 25 and parts of the Flagstaff City Code. This update does not alter the intent of FRP30; it is only concerned with correcting errors, removing legal vulnerability, and improving the readability of FRP30.

The objective of this study was to evaluate the effect of typical chemical winter maintenance practices on Arizona Department of Transportation pavements. A review of previous studies on the effect of deicing/anti‐icing chemicals did not yield definitive recommendations, especially for DIAICs typically used by ADOT. Researchers conducted a laboratory study evaluating the effects of magnesium chloride, potassium chloride, sodium chloride, and distilled water on eight different open‐graded rubber‐modified asphalt concrete mixes using the boiling test. All experimental factors were found to be statistically significant, and the researchers provide recommendations on which DIAICs should be used for different binder and aggregate types.

Land Use and Traffic Congestion is an investigation into the links among land use, travel behavior, and traffic congestion. Researchers focused on four transportation corridors in the Phoenix area: three older neighborhoods with relatively mixed, higher density land use, and one suburban area with lower density but high traffic volumes. The analysis suggested that the higher density corridors exhibited less congestion due to the greater mix of uses, shorter trip lengths, more travel by transit and non-motorized modes, and the presence of a secondary street grid system.

As part of the Long Term Pavement Performance (LTPP) Program, the Arizona Department of Transportation constructed eight Specific Pavement Studies 9 (SPS‐9) test sections on Interstate 10 near Phoenix is an overlay project and is accordingly given independent analysis and documentation in this report separate from Arizona SPS‐9B projects located on US 93, which were new construction and are documented in a separate report. The SPS‐9A project studied the effect of asphalt specification and mix designs on flexible pavements, specifically comparing Superpave binders with commonly used agency binders. Opened to traffic in 1995, the project was monitored at regular intervals until it was rehabilitated in 2005. Surface distress, profile, and deflection data collected throughout the life of the pavement were used to evaluate the performance of various flexible pavement design features, layer configurations, and thickness. This report documents the analyses conducted as well as practical findings and lessons learned that will be of interest to ADOT.