sr 77/oracle road multimodal corridor profile study final report - Pima ...

5.1.4 Pavement Type and Condition
Data on the pavement type and year built for SR 77 were obtained from the State Highway
System Log. Exhibit 5-5 summarizes pavement type data for SR 77. Pavement condition data
were obtained from the current Highway Performance Monitoring System data on SR 77. The
condition of pavement is measured by the Pavement Serviceability Rating (PSR) with qualitative
descriptors measuring the quality of the observed pavement. PSR ratings are from 5.0, which is
a new and distress free (sufficiently free of cracks and patches) pavement, to a PSR rating of 0.0
which represents pavements in extremely deteriorated conditions, passable only at reduced
speeds, and with considerable ride discomfort. Large potholes and deep cracks exist on
pavements with PSR ratings close to 0.0. The PSR ratings for the project section of SR 77 are
shown in Exhibit 5-6.
As shown in the exhibit, most of the segments on SR 77 have a PSR rating over 3.0, representing
pavements that exhibit few, if any, visible signs of surface deterioration. The segments between
MP 69.80 and MP 71.30 have PSR ratings slightly under 3.0; however, these segments were part
of a recently completed pavement overlay project.
5.1.5 Structures
Bridge condition data were obtained from the ADOT Information Data Warehouse (AIDW)
bridge data which is maintained by the ADOT Bridge Group. There are 23 structures in the
Bridge Record that are on SR 77 within the corridor. These include a traffic interchange (with a
railroad overpass), drainage structures and bridges over rivers. Sufficiency ratings (also shown
in the list of structures) are used to determine a structure’s condition. The bridge sufficiency
rating is expressed as a percentage in which 100 percent would represent an entirely sufficient
bridge and zero percent would represent an entirely insufficient bridge. Bridges with sufficiency
ratings below 80 percent are classified as structurally deficient structures and are eligible for
rehabilitation. Bridges with sufficiency ratings below 50 percent may need replacement. Exhibit
5-7 is a table identifying bridge sufficiency ratings and descriptions of the ratings. A list of all
the structures on SR 77 in the corridor is shown in Exhibit 5-8.
In addition to structurally deficient structures, there are functionally obsolete structures.
Functionally obsolete structures include bridges with horizontal and vertical clearances which
met AASHTO clearance standards when originally constructed, but which may not meet updated
standards for both sets of clearances.
Twelve of the 22 structures have a sufficiency rating at or below 80 percent and are thus eligible
for rehabilitation. These are listed in Exhibit 5-8.
5.1.6 Drainage
Pinal County Line to Oracle
As State Route 77 continues north from the Pinal County line to the Town of Oracle, it transects
both local and regional watersheds which lie east of Big Wash (see Exhibit 5-9). Throughout
this stretch at-grade and culvert crossings serve to convey the flow to the west. Of these
numerous crossings, nine have been identified as primary watersheds, with five of these
SR 77/Oracle Road Multimodal Corridor Profile Study May 2007
Final Report Page 5-6