This chapter contains the results of traffic volume estimates carried out for the same road segments for which the representative annualized road costs were estimated. Traffic volume estimates were obtained through the responses to the Provincial Highway Inventory survey and the subsequent communication with the provincial and territorial representatives. The results are presented in the Road Inventory Sheets introduced in Chapter 4 as Table 4, and presented in Appendix C. There is one one-page Road Inventory Sheet for each province or territory. Québec, Ontario, and British Columbia have a two-page Road Inventory Sheets because each of these provinces was subdivided into two geographical regions.
Results
An example of traffic data reporting format used for the Road Inventory Sheets is shown in Table 15.
Table 15 was extracted from the Road Inventory Sheet for Ontario.
Table 15. Example of Traffic Data Reporting Format AADT volumes for Southern Ontario, average and range
Average Range Average Range
Freeway 64,425 5,450 - 102,600 70,847 17,400-410,000
Arterial 12,053 610 - 46,000 12,978 5,700 - 41,700
Collector 7,604 650 - 50,400 5,689 2,050-33,300
Local 9,917 150 - 22,300
Percent commercial vehicles, average and range
Average Range Average Range
Freeway 21.6% 3.0 - 50.8% 11.5% 4.2 - 20.0%
Arterial 10.5% 3.3 - 33.3% 9.6% 3.2 - 21.8%
Collector 10.3% 2.8 - 26.8% 10.4% 2.0 - 19.6%
Local 9.6% 3.9 - 30.4%
Rural Urban
Provincial Roads, Southern Ontario
Rural Urban
Functional Class
Provincial Roads, Southern Ontario Functional
Class
The following traffic characteristics are reported on the Road Inventory Sheets given in Appendix C:
• Average AADT (Annual Average Daily Traffic) volume;
• Range of AADT volumes;
• Average AADT of commercial vehicles (trucks and buses); and
• Range of AADT of commercial vehicles.
The traffic characteristics are typically for year 2003 or for the most recent year for which data were available.
The Use and Definition of Traffic Data
Traffic characteristics, such as traffic speed and volume, are important considerations for classifying road network by functional class. For example, arterial roads are typically associated with high traffic volumes of cars and commercial vehicles and with high traffic speeds. Traffic volumes are also required for estimating road costs per vehicle kilometre of travel.
Road costs per vehicle km of travel depend mainly on traffic volumes rather than on road costs. For example, the cost of a freeway lane is typically about 3 or 4 times higher than the corresponding costs of a traffic lane on a collector road. On the other hand, the traffic volume on a freeway lane can be about 100 times higher than traffic volume on a collector lane. The difference in traffic volumes is even larger for truck traffic. Truck traffic (in terms the Equivalent Single Axle Loads, a measure of pavement damage caused by trucks) can be 1000 times higher on a freeway lane than on a collector lane. Consequently, road costs per vehicle km of travel are effectively governed by the assumptions made regarding traffic volumes.
In order to estimate road costs per vehicle km of travel for different road functional classes and categories, it is necessary to know traffic volumes associated with these classes and categories.
Annual Average Daily Traffic (AADT) Volume
Canadian provincial highway agencies typically estimate AADT using the AASHTO method [9].
According to the AASHTO method, for each month of the year, seven monthly average days of the week are computed. (All Mondays for a month are averaged, all Tuesdays for a month are averaged, etc.) Then the twelve Mondays are averaged, the twelve Tuesdays are averaged, etc. This results in seven yearly average days of the week, which are averaged to obtain an annual average daily volume estimate.
AADT volumes are reported as a combined volume for all vehicles (motorcycles, passenger cars, buses, and trucks) and for all traffic lanes in the highway corridor (all lanes in both directions).
AADT of Heavy Vehicles
Canadian provincial highway agencies do not use a standard method to classify highway vehicles.
However, the agencies, through their participation in SHRP (Strategic Highway Research Program) and C-SHRP (Canadian SHRP) Long term Pavement Performance Studies, are familiar with and tend to use the United States Federal Highway Administration classification of highway vehicles [10]. This classification is presented in Table 16.
All vehicles listed in Table 16 (Vehicle classes 4 to 13) are considered to be commercial vehicles and are included in the AADT of commercial vehicles given on the Road Inventory Sheets.
Table 16. FHWA Commercial Vehicle Classification (Based on Reference 10) Vehicle Class Typical Configuration Description
4 Buses
5 Two-Axle, Six-Tire, Single Unit Trucks
6 Three-Axle Single Unit Trucks
7 Four or More Axle Single Unit Trucks
8 Four or Less Axle Single Trailer Trucks
9 Five-Axle Single Trailer Trucks
10 Six or More Axle Single Trailer Trucks
11 Five or Less Axle Multi-Trailer Trucks
12 Six-Axle Multi-Trailer Trucks
13 Seven or More Axle Multi-Trailer Trucks
Data Challenges
This section contains background information on traffic data summarized in the Road Inventory Sheets given in Appendix C. The main data deficiencies are in the area of traffic volumes on municipal roads. It appears that provincial agencies do not have records of traffic usage on municipal roads. ARA has obtained traffic data from several municipalities. However, traffic data obtained from individual
municipalities are insufficient for the estimation of traffic characteristics that would be applicable across the entire municipal road network within a province or a territory.
Newfoundland and Labrador
Only traffic data for provincial arterial roads were received.
Prince Edward Island
No traffic data were received from Prince Edward Island.
Nova Scotia
Traffic data were received for provincial roads (per road functional classes).
New Brunswick
No traffic data were received traffic data from New Brunswick.
Québec
Québec provided a complete set of traffic data for provincial roads. The data are reported for one combined region.
Ontario
Ontario provided a complete set of traffic data for provincial roads.
Manitoba
Manitoba provided a complete set of AADT data for provincial roads. Data for the AADT of commercial vehicles were incomplete.
Saskatchewan
Saskatchewan provided a complete set of traffic data for provincial roads.
Alberta
Alberta provided a complete set of traffic data for provincial roads.
British Columbia
No traffic data were received from British Columbia.
Yukon Territory
Yukon Territory provided a fairly complete set of traffic data for territorial roads.
Northwest Territories
Northwest Territories provided a complete set of AADT data for territorial roads. AADT of commercial vehicles was not provided.
Nunavut
No traffic data were received from Nunavut.