The Oregon DOT estimated that weigh-in-motion and electronic screening systems at 21 weigh stations can save motor carriers more than $600,000 per year in fuel costs and increase annual freight transport by more than two million miles.

Oregon DOT experience with the ""Green Light"" electronic screening program.

Date Posted

Oregon Department of Transportation ""Green Light"" Emission Testing Project

Summary Information

In Oregon, windshield mounted transponders were distributed to registered motor carriers and electronic screening systems were installed at 21 weigh stations. The program known as Green Light used weigh-in-motion (WIM) scales and automated vehicle identification (AVI) technology to enable truckers to bypass weigh stations at highway speeds if their truck passed an instantaneous check of size, weight, height, registration, road use tax account status, and safety records. Drivers were signaled with an in-cab device whether to "Report" to the station or "Bypass".

This study examined the overall benefits of the Green Light program and extrapolated the results to estimate impacts at weigh stations across the state.

On June 17, 2008 a field test was conducted. The Oregon DOT supplied and operated a Class 8 diesel powered truck (2004 Volvo D12) configured with a lowboy trailer carrying steel plate having a gross weight of 51,700 pounds. The test area included the Woodburn weigh station and a section of I-5 from the Aurora/Donald interchange at milepost 278 to the Woodburn interchange at milepost 271. A Portable Emission Measurement System (PEMS) was used to measure fuel consumption and emissions of Nitrogen oxides (NOx) Carbon monoxide (CO) Carbon dioxide (CO2) and particulate matter (PM10 or less). Emission measurements were collected at highway speeds and transitional speeds at weigh stations. Data were collected on ten highway segments and five weigh station segments. The impacts of pre-clearance were quantified.


Findings indicated that a million bypasses can save approximately $400,000 in fuel costs and increase freight transport by 1.5 million miles. Since approximately 1.5 million bypasses were processed by the entire Green Light program in 2008, the system saved approximately $600,000 per year in carrier fuel costs and increased annual freight transport by approximately two million miles at all 21 weigh stations across the state.