Annual Traffic Volume Report Central Region 1998 • 1999 • 2000 Alaska Department of Transportation & Public Facilities Whittier Tunnel The town of Whittier lies among glacier covered mountains along the Prince William Sound, about 47 miles southeast of Anchorage. The town, with a population of 280 people, is connected to the Seward Highway by Portage Glacier Road and the Anton Anderson Whittier tunnel. Whittier is a deep water, ice-free port, and is part of the Alaska Marine Highway system. The railroad from Whittier to Portage was constructed by the U.S. Army in 1941 and was used as the main supply line for the Second World War. It was built under the direction of an Army engineer named Anton Anderson, for whom the tunnel is named. The military remained in Whittier until the 1950’s. After the military’s departure, private ownership of land became possible. During the mid 60’s, the Alaska Railroad began operating a train between Portage and Whittier. Residents and visitors were able to load their vehicles and ride the train through the narrow tunnel. The expansion of the tunnel to allow vehicle traffic as well as trains, began in 1998 and was completed in 2000. The American Society of Civil Engineers awarded the tunnel with the 2001 Outstanding Civil Engineering Achievement (OCEA) Award. The tunnel was selected from among 17 other projects around the United States. The tunnel is a 2.5 miles long passageway through Maynard Mountain, making it the longest highway tunnel in North America. It consists of a one lane road with the railroad being part of the road. The direction of traffic changes each half hour with the train using the tunnel twice a day. As part of the safety precautions, the tunnel contains 50 cameras to monitor traffic, safe houses at 1600 foot intervals, and telephones all along the tunnel. For more information on the town of Whittier or the Anton Anderson Whittier Tunnel, check out the following links: Whittier http://www.ci.whittier.ak.us/ Tunnel http://www.dot.state.ak.us/whittiertunnel/ ALASKA DEPARTMENT OF TRANSPORTATION AND PUBLIC FACILITIES CENTRAL REGION PLANNING HIGHWAY DATA SECTION CENTRAL REGION TRAFFIC VOLUME REPORT 1998, 1999, AND 2000 A SUMMARY OF TRAFFIC DATA COLLECTED ON STATE ROADS (AND SOME LOCAL ROADS) IN THE CENTRAL REGION This Page Left Intentionally Blank ANNUAL TRAFFIC VOLUME TABLE OF CONTENTS Part I Introduction Part II Road Listings by Route Name and by Route Number Part III Annual Average Daily Traffic (AADT) Part IV Permanent Traffic Recorder (PTR) Summaries Part V Vehicle Classification Data Part VI Temperature Probe Data This Page Left Intentionally Blank Part I Introduction This Page Left Intentionally Blank Introduction The Highway Data Section provides data describing the volumes (number of vehicles) and other characteristics of traffic over the state highway system for use by engineers, planners, administrators, and others whose work requires such information. The traffic data program includes the collection of count data, data editing, data processing, analysis, report preparation, data distribution, computer traffic modeling, traffic forecasting, equipment installation and maintenance, data file maintenance, and the annual planning of activities. The Central Region contains the largest concentration of population in the State of Alaska, and is the most far-flung of the three Regions. The contiguous highway system runs from the Homer Spit at the end of the Sterling Highway to the Regional boundaries on the Glenn Highway at MP 118 near Eureka, and the Parks Highway at MP 163 at Little Coal Creek. It includes Kodiak Island and the Aleutian Chain, as well as the isolated villages south of the Kuskokwim River, and all points in between. The following report is a summary of the data collected in the Central Region from 1998 through 2000. The key elements are: Permanent Counts: Traffic volumes, by direction of travel, collected year-round with Automatic Traffic Recorders (ATRs) at a number of permanently established locations. These counts are summarized yearly and used to provide seasonal adjustment factors applicable to coverage counts recorded at all other locations. Coverage Counts: Traffic volumes, sometimes by direction of travel, are typically collected for seven days, with a minimum of one weekend and one weekday. These counts are on a cycle of one to three years at selected locations on the state, borough, and municipal road system. Most coverage counts are taken between May and September because the weather related road conditions make counting very difficult the remainder of the year. Because summer traffic is generally much higher than other times of the year, the counts are adjusted for weekday and seasonal variations using one or more associated permanent traffic recorders (PTR's) to obtain an estimated Annual Average Daily Traffic (AADT). The calculated AADT then represents the traffic on the specific traffic link on which the count was taken. Vehicle Classification Counts: Traffic volume counts that classify all vehicles by type, based on the axle arrangement, number of trailers, and other vehicle characteristics. Class counts are collected for a periods of time ranging from 16 hours to seven days or more. At key permanent locations data is collected throughout the year using permanently installed detectors and counters. Weigh-In-Motion (WIM): Traffic counts which classify all vehicles by the same criteria as the vehicle classification counts, but include the added dimension of axle weights for all commercial size vehicles. The Highway Data Section conducted tests on several WIM systems in 1990 and 1991. The installation of several of these systems provides data specifically for road design, monitoring design and material performance, and testing of experimental materials and pavement design. WIM data is not included in this report. Annual Traffic Volume Report I - 1 This year the Department of Transportation and Public Facilities continued to implement changes of route naming and numbering of roads in the CDS Roadlog database. The purpose was to make the database more user friendly by assigning route numbers that reflect current road names as assigned by local communities. Previous to these changes, some numbered routes included up to 7 different roads or parts of different roads. The analysis and inventory of all the routes is not complete, but this document contains the latest changes implemented. Part II contains a cross- reference of road names and CDS road numbers. This report sorts and lists information by Route Number. Annual Traffic Volume Report I - 2 Definitions: Annual Average Daily Traffic (AADT): The estimated number of vehicles traveling over a given road segment during one 24 hour day. In practice, AADT is usually obtained from a sample (coverage count) adjusted for seasonality. Automatic Polling: A method of obtaining data from automatic counters by telephone from a central computer location with automatic dialing equipment. Automatic counters in the field must have microprocessor memory and telephone connection. Automatic Vehicle Classifier (AVC): Traffic counting equipment which automatically counts and classifies vehicles passing over its detectors, providing a record of those volumes by specific time intervals and vehicle classes. Axle-Body Combination: A vehicle description based on the configuration of axles, leading and trailing units, and tractor body. Axle Correction Factor: The proportion by which a volume count based on axles (e.g., from pneumatic tube detectors) is multiplied to obtain an estimate of the number of actual vehicles. The ratio is 1.0 or less, and is derived from vehicle class counts. Collector: A road classification applicable to roads serving a mixture of local access and through traffic, for which the volume, average speed, and trip length of vehicles using the road are usually lower than for principal or minor arterials, but higher than for local roads. Coverage Count: Hourly (sometimes directional) total traffic volumes collected for a three-to-seven day period on a cycle of one to three years. Counts are generally done with a portable automatic traffic counter using pneumatic-tubes (hoses) or inductive loops in the road. Locations of counts remain the same from one rotation year to the next. Highway Performance Monitoring System (HPMS): The data reporting system developed by the Federal Highway Administration (FHWA) for standardized road inventory, physical condition, and traffic use monitoring by all states. Interstate Highway: A highway within the principal arterial category that is also designated as part of the Federal Interstate Highway System. Link: A section of a road for which traffic data is reported. Link termini are located so that the traffic volume is roughly constant on a link. Link Volume: The number of vehicles passing over a highway link in a given time interval. Time intervals may range from 5 minutes to 24 hours, as observed or as averaged over longer periods. Local Road: Any street or highway (regardless of ownership) which is not classified as any higher type of arterial or collector road. Local roads serve mostly local-access movements, at lower speeds and volumes than roads of other classifications. Annual Traffic Volume Report I - 3 Minor Arterial: A street or highway serving mostly through movements, but with shorter trip lengths and at lower speeds than principal arterials. Monthly Average Daily Traffic (MADT): The estimated average daily traffic volume for a specific month at a given location. Permanent Count: Hourly, directional or non-directional total traffic volumes collected year-round with Permanent Traffic Recorders (PTR) at established locations. These counts are used to adjust coverage counts for seasonal variations to yield AADT's. Permanent Detector: A vehicle detector that is permanently installed in a roadway, as compared to a portable detector. The most common permanent detector equipment employs an inductive loop that senses a vehicle's presence as a change in the electrical characteristics of the loop.