Abstract

• Detailed explanation of errors in speed correction factors (SCFs) • Quantifying the impact of vehicle specific power (VSP) distribution on SCFs. • Quantitative analysis of relationship between emission rate and SCFs. Speed correction factors (SCFs) reflect the impact of traffic conditions on vehicle emissions. However, uncertainty often occurs when calculating SCFs in existing emission models. Investigating how uncertainty occurs is helpful in improving accuracy when calculating SCFs. This study calculates SCFs of carbon dioxide (CO 2 ) of non-hybrid light-duty vehicles on urban restricted access roadways, and analyzes two important explanatory variables when calculating SCFs: speed-specific vehicle specific power (VSP) distributions and emission rates. The characteristics of how SCFs change in response to changes in VSP distributions and emission rates are discussed in detail. The results show that distortions in VSP distributions and emission rates significantly affect SCFs. A 1% change of the fraction in a VSP bin or a 1% change in the average emission rate in a VSP bin can cause 1.3–3.2% or 0.08–0.13% of changes in SCFs, respectively. These findings are helpful in reducing uncertainty when calculating SCFs.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.