# Traffic Counts

Note: Traffic counts cover various street segments and are provided for informational purposes only. All data should be verified with the appropriate Traffic Operations staff at (707)441-4194, and/or verified in the field, prior to use. The last comprehensive counts were conducted in 1997. Some street segments are more current as the date indicates. The City of Eureka uses a 1.4% per year growth rate as a rule of thumb.

A growth factor can be used to adjust the traffic volumes. The raw volume data is multiplied by the growth factor when calculating Adjusted volumes and Lane Group volumes.

Current volumes can be adjusted to future volumes with the Growth Factor. To calculate a growth factor based on a growth rate over several years, use the following formula:

GF = (1+r)^Y = Growth Factor

r = Growth Rate

Y = Number of years

For example the growth factor for 1.4% growth over 8 years is:

GF = (1 + 0.014) ^ 8 = 1.118

A street segment showing a traffic count of 1000 in 1997 would be adjusted as follows:

Adjusted volume = 1000 x 1.118 (GF) = 1118