# join the people threads and collect statistics
    my ($total_wait, $total_ride, $max_wait, $max_ride) = (0,0,0,0);
    foreach (@people) {
        my ($wait1, $wait2, $ride1, $ride2) = $_->join;
        $total_wait += $wait1 + $wait2;
        $total_ride += $ride1 + $ride2;
        $max_wait    = $wait1 if $wait1 > $max_wait;
        $max_wait    = $wait2 if $wait2 > $max_wait;
        $max_ride    = $ride1 if $ride1 > $max_ride;
        $max_ride    = $ride2 if $ride2 > $max_ride;
    }