_dta:
  1.  by Jean Roth , jroth@nber.org , 1 Sep 2016

  obs:        48,959                          
 vars:             4                          1 Sep 2016 13:59
 size:       342,713                          (_dta has notes)
---------------------------------------------------------------------------------------------------------------
              storage   display    value
variable name   type    format     label      variable label
---------------------------------------------------------------------------------------------------------------
state           byte    %8.0g                 state number
st_case         long    %12.0g                consecutive number
veh_no          byte    %8.0g                 vehicle number
mvisobsc        byte    %8.0g                 driver(s) vision obscured by
---------------------------------------------------------------------------------------------------------------
Sorted by: st_case  veh_no  mvisobsc