Description

The data comes from a unpublished master's paper by Carl Hoffstedt. They relate the automobile accident rate, in accidents per million vehicle miles to several potential terms. The data include 39 sections of large highways in the state of Minnesota in 1973. The goal of this analysis was to understand the impact of design variables, Acpts, Slim, Sig, and Shld that are under the control of the highway department, on accidents.

Usage

Format

This data frame contains the following columns:

rate

1973 accident rate per million vehicle miles

len

length of the Highway1 segment in miles

adt

average daily traffic count in thousands

trks

truck volume as a percent of the total volume

sigs1

(number of signalized interchanges per mile times len + 1)/len, the number of signals per mile of roadway, adjusted to have no zero values.

slim

speed limit in 1973

shld

width in feet of outer shoulder on the roadway

lane

total number of lanes of traffic

acpt

number of access points per mile

itg

number of freeway-type interchanges per mile

lwid

lane width, in feet

htype

An indicator of the type of roadway or the source of funding for the road, either MC, FAI, PA, or MA

Source

Carl Hoffstedt. This differs from the dataset Highway in the alr4 package only by addition of transformation of some of the columns.

References

Fox, J. and Weisberg, S. (2019) An R Companion to Applied Regression, Third Edition, Sage.

Weisberg, S. (2014) Applied Linear Regression, Fourth Edition, Wiley, Section 7.2.