Traffic Data
Whatcom County Traffic Count Manual (2007)
- Click what types of roads you would like to see counts for. Clicking "all" will show you all available traffic counts in Whatcom County.
- Please be patient as the map generates.
- Use the arrows on the left of the map to move around the map, and the + and - signs to zoom in and out. If you click the "zoom..." button, you will be able to highlight a region on the map and zoom in to that entire region. You can also use the "hand" on the map to grab and move around the map.
- Click on any specific traffic count marker to get the latest daily count. If a previous count is available, both counts will be displayed along with the percent change between the two years.
Whatcom County Traffic Counts
This map is a compilation of traffic count information for selected roads within Whatcom County. The information was provided by Whatcom County and the Cities of Bellingham, Blaine, Everson, Ferndale, Lynden, Nooksack and Sumas. The Washington State Department of Transportation (WSDOT) provided counts for State Routes. The purpose of this map is to provide basic traffic data characterizing both existing and historical conditions to give the reader a sense of scale of demand for road transportation, and to show where that demand has been static, increasing, or in some cases, decreasing. The information portrayed here was gathered by multiple agencies using multiple methodologies, and is assembled for general information purposes only. It is not intended to be statistically significant or to be used for scientific purposes. The previous Whatcom County Traffic Manual was produced in 2002.
An important component of transportation planning is the number of vehicles that use specific roadways within a jurisdiction. This data can be used to correct deficiencies in transportation systems. Traffic counts shown in this report are computed from short term counts; their degree of accuracy is acceptable only for showing yearly trends. Traffic data used for design purposes should be obtained by specific requests to the appropriate jurisdiction.
While the preparation of this document was financed in part by the Federal Transit and Federal Highway Administrations, within the US Department of Transportation, the content is entirely the responsibility of the WCOG. Any comments on the data portrayed can be directed to:
Whatcom Council of Governments
314 E. Champion St.
Bellingham, WA 98225
(360) 676-6974
Mechanics of Traffic Counts
Traffic counts are defined as the number of vehicles passing a given point in a specific period of time. There are a variety of ways to both count traffic, and to calculate a daily average for comparison purposes. Weekday traffic counting is the predominate data gathering method used by Whatcom County jurisdictions. With this method, counts are taken only on weekdays, not weekend days. Weekly traffic counts include traffic for all seven days of a week. Traffic count data may also be used to identify peak flow periods, usually am or pm peaks.
This map portrays two types of traffic volume information: Average Daily Traffic (ADT) and Annual Average Daily Traffic (AADT). ADT is the method used by most jurisdictions in Whatcom County, and is arrived at by dividing the number of vehicles passing a given point in a specific time frame by the number of hours in that time frame and multiplying the results by 24 hours. WSDOT uses the AADT for counts on State highways. AADT is used when count data is available for longer periods of time, such as at permanent counter installations, and reflect both seasonal, and day to day variations in traffic flow. AADT is calculated using an annualized count and dividing by 365.
The traffic data is shown in table and map format and the ADT counts are either weekday or weekly in type. Unless noted otherwise, traffic counts are bi-directional for all lanes. The description column shows the location of the traffic count. All counts included in this map are from the two most recent count years from each jurisdiction. A significant variation in time period between counts is evident with periods as long as eighteen years.
Whatcom County and its Cities differ widely in how traffic counting activities are scheduled. Some have a specific schedule, while others are constrained by resources including equipment and staff time. Counts shown for cities that host State Highways may include both AADT and ADT traffic count numbers.
Any comments or questions concerning this map should be directed to the Whatcom Council of Governments.