The Lacombe truck study was completed on Wednesday, October 23, 2002 from approximately 09:00 to 18:00.
For the purposes of this survey a truck was defined as any vehicle larger than a pick up truck. The discriminating factor for smaller vehicles was the distinction whether a pickup sized vehicle included a factory installed pickup box or whether an aftermarket flat deck or service body was attached to the vehicle. Some pickups towing trailers were included in the survey data, however, it was not clear whether they were consistently recorded at all survey positions and, therefore, all pickup/trailer data was expunged from the survey prior to analysis.
School buses were also observed during the survey, however, they were determined to be local vehicles and their travel patterns were directionally opposed to the truck travel (in other words, the buses tended to leave town and then return). For the most part, the bus travel patterns were inbound and outbound through the same intersection. As the purpose of the survey was to identify truck travel through the town all school bus trips were removed prior to analysis.
A total of four survey locations were manned continuously by teams of three surveyors. A supervisor was assigned to each end of the survey route and during peak periods the supervisors assisted with data collection. Each survey team utilized binoculars to aid in the collection of vehicle characteristics. All survey locations were located on Highway 12, with one team deployed east of the Highway 2 interchange, and a second team deployed west of the intersection of Highway 2A and Highway 12. At the interchange, both the east and west bound travel lanes were reduced to one lane in each direction and the speed limit was reduced to 50 km/hr. At the Highway 2A/12 intersection, “Men Working” signs and pylons were deployed to restrict the width of the travel lane in an attempt to slow vehicles down. Data was collected for all larger vehicles past each of the survey points.
While data was collected for every large vehicle, it was not possible to collect complete data for every vehicle due to dirt, speed and number of vehicles in a platoon. The greatest difficulty encountered was with license plates as they were often dirty, covered or missing entirely on trailers and larger vehicles. Whenever possible, front plates were recorded as well. Another difficulty with collecting license plate data in Alberta is the requirement for vehicles to only display rear license plates. This was compounded further on large vehicles because plates were not consistently located on all vehicles. Due to the downhill grade westbound Highway 12 vehicles near the Highway 2 interchange appeared to traverse the work zone at a higher rate of speed than in the eastbound direction.