Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Fraction of traffic emissions attributable by vehicle class (HDDV = heavy-duty diesel vehicles; LDDT = light-duty diesel trucks; LDDV = light-duty diesel vehicles; MC = motorcycles; HDGV = heavy-duty gasoline vehicles; LDGT2 = light-duty gasoline trucks type 2; LDGT1 = light-duty gasoline trucks type 1; LDGV = light-duty gasoline vehicles).
