Traffic                 package:MASS                 R Documentation

_E_f_f_e_c_t _o_f _S_w_e_d_i_s_h _S_p_e_e_d _L_i_m_i_t_s _o_n _A_c_c_i_d_e_n_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     An experiment was performed in Sweden in 1961-2 to assess the
     effect of a speed limit on the motorway accident rate.  The
     experiment was conducted on 92 days in each year, matched so that
     day `j' in 1962 was comparable to day `j' in 1961.  On some days
     the speed limit was in effect and enforced, while on other days
     there was no speed limit and cars tended to be driven faster. The
     speed limit days tended to be in contiguous blocks.

_A_r_g_u_m_e_n_t_s:

    year: 1961 or 1962 

     day: of year 

   limit: was there a speed limit? 

       y: traffic accident count for that day 

_F_o_r_m_a_t:

     This data frame contains the following columns:

_S_o_u_r_c_e:

     Svensson, A. (1981) On the goodness-of-fit test for the
     multiplicative Poisson model. Annals of Statistics, 9 697-704.

