amis                  package:boot                  R Documentation

Car Speeding and Warning Signs

Description:

     The 'amis' data frame has 8437 rows and 4 columns.

     In a study into the effect that warning signs have on speeding
     patterns,  Cambridgeshire County Council considered 14 pairs of
     locations. The locations were paired to account for factors such
     as traffic volume and type of road.  One site in each pair had a
     sign erected warning of the dangers of speeding and asking drivers
     to slow down.  No action was taken at the second site.  Three sets
     of measurements were taken at each site.  Each set of measurements
     was nominally of the speeds of 100 cars but not all sites have
     exactly 100 measurements. These speed measurements were taken
     before the  erection of the sign, shortly after the erection of
     the sign, and again after  the sign had been in place for some
     time.

Usage:

     amis

Format:

     This data frame contains the following columns:

     'speed' Speeds of cars (in miles per hour).

     'period' A numeric column indicating the time that the reading was
          taken. A value of 1 indicates a reading taken before the sign
          was erected,  a 2 indicates a reading taken shortly after
          erection of the sign and a 3 indicates a reading taken  after
          the sign had been in place for some time.

     'warning' A numeric column indicating whether the location of the
          reading was chosen to have a warning sign erected. A value of
          1 indicates presence of a sign and a value of 2 indicates
          that no sign was erected.

     'pair' A numeric column giving the pair number at which the
          reading was taken. Pairs were numbered from 1 to 14.

Source:

     The data were kindly made available by Mr. Graham Amis,
     Cambridgeshire County Council, U.K.

References:

     Davison, A.C. and Hinkley, D.V. (1997)  _Bootstrap Methods and
     Their Application_. Cambridge University Press.

