Transportation Statistics and Microsimulation

Inferences Concerning Categorical Data    ◾    167

dierent values of one variable, and the columns indicate the values of

another variable. A contingency table having I rows and J columns is oen

referred to as an I × J table.

As part of a TxDOT-sponsored research project to develop guidance

materials on intermediate access to a buer-separated toll lane, research-

ers recorded whether a driver used the turn signal during the maneuver

(Fitzpatrick et al., 2007). A contingency table for access maneuver at an

HOV lane (abort, in, out, or passing) and use of turn signal (yes, no) is

shown in Table 9.2. is is a 4 × 2 contingency table. Table 9