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Publication Number: FHWA-RD-95-176
Date:November 1996

Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Task Analysis of ATIS/CVO Functions

 

APPENDIX B. FUNCTION AND SCENARIO SELECTION

 

Functional Characteristics Included in the Commercial Vehicle Task Analysis

Frequency Count

A similar analysis using the matrix of information flows between functions (see table 32) was performed for the ATIS/CVO functional characteristics appropriate for commercial drivers. The results of the rank ordering of each function according to interactions with other functions are listed in table 33. Once more, the functions are ranked from those with the most interactions to those with the least. This table indicates that dispatch is the most frequent interacting function, closely followed by the pre–drive route and destination selection, which also happened to be the most frequent interacting function for the private vehicle operations.

Table 32. Information flows between functions for commercial vehicle operations.

INPUTS

OUTPUTS

 

IRANS

IMSIS

ISIS

IVSAWS

CVO

TOTAL

 

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

6.1

6.2

6.3

6.4

7.1

7.2

7.3

7.4

8.1

8.2

8.3

8.4

8.5

8.6

9.1

9.2

9.3

9.4

 

IRANS

5.1

0

1

1

0

0

1

0

0

1

0

1

0

1

1

0

0

0

1

0

0

0

0

1

1

1

1

12

 

5.2

0

0

1

1

0

0

0

1

0

0

1

0

0

0

0

0

0

0

0

0

0

0

1

1

1

1

8

 

5.3

0

0

0

0

1

1

0

1

1

0

1

0

1

1

0

0

0

1

0

0

0

0

1

1

1

1

12

 

5.4

0

0

0

0

1

0

0

0

0

0

1

0

1

1

0

0

0

1

0

0

0

0

1

1

0

0

7

 

5.5

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

 

5.6

0

1

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2

 

5.7

1

1

1

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

0

6

 

5.8

0

0

1

1

0

1

0

0

1

0

1

1

0

0

0

0

0

1

0

0

0

0

1

1

1

1

11

 

IMSIS

6.1

0

0

0

1

0

1

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

3

 

6.2

1

1

1

0

0

1

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

5

 

6.3

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

1

0

0

2

 

6.4

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

0

0

3

 

ISIS

7.1

0

0

0

0

1

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2

 

7.2

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

 

7.3

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

 

7.4

1

0

1

1

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

0

0

6

 

IVSAWS

8.1

0

0

0

1

0

1

0

0

0

0

0

0

1

0

0

0

0

0

0

1

0

0

0

0

0

0

4

 

8.2

1

1

1

1

0

1

0

1

0

0

1

1

1

0

0

0

0

0

0

1

0

0

1

1

0

0

12

 

8.3

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

1

0

0

0

0

0

1

1

1

0

5

 

8.4

0

0

0

0

0

0

0

0

0

1

1

1

0

0

0

1

0

0

0

0

0

1

1

0

0

0

6

 

8.5

0

0

0

1

0

0

0

1

1

1

0

0

0

0

0

0

0

0

1

1

0

0

1

1

1

1

10

 

8.6

0

0

0

1

0

0

0

1

1

1

0

0

0

0

0

0

0

0

1

1

0

0

1

1

1

1

10

 

CVO

9.1

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

1

0

0

2

 

9.2

0

0

1

1

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

1

0

1

0

5

 

9.3

1

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

1

4

 

9.4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

1

1

0

3

TOTAL

5

5

8

11

3

10

0

8

5

3

9

6

5

3

0

2

1

4

2

4

0

1

13

16

10

7

 
     
 

17

13

20

18

3

12

6

19

8

8

11

9

7

4

0

8

5

16

7

10

10

11

15

21

14

10

INTERACTION

TOTAL

 

5

9

2

4

25

10

22

3

18

18

11.5

16

20.5

24

26

18

23

6

20.5

14

14

11.5

7

1

8

14

RANK

 

Table 33. Rank ordering of the commercial functional characteristics.

RANK

FUNCTION

SYSTEM

1

9.2 Dispatch

CVO-specific

2

5.3 Pre-drive route and destination selection

IRANS

3

5.8 Route scheduling

CVO-specific

4

5.4 Dynamic route selection

IRANS

5

5.1 Trip planning

IRANS

6

8.2 Road condition information

IVSAWS

7

9.1 Fleet resource management

CVO-specific

8

9.3 Regulatory administration

CVO-specific

9

5.2 Multi-mode travel coordination

IRANS

10

5.6 Route navigation

IRANS

11.5

6.3 Destination coordination
8.6 Cargo and vehicle monitoring

IMSIS
IVSAWS

14

8.4 Manual aid request
8.5 Vehicle condition monitoring
9.4 Regulatory enforcement

IVSAWS
IVSAWS
CVO-specific

16

6.4 Message transfer

IMSIS

18

6.1 Broadcast services/attractions
6.2 Services/attractions directory
7.4 Road restriction information

IMSIS
IMSIS
CVO-specific

20.5

7.1 Guidance information
8.3 Automatic aid request

ISIS
IVSAWS

22

5.7 Automated toll collection

IRANS

23

8.1 Immediate hazard warning

IVSAWS

24

7.2 Notification information

ISIS

25

5.5 Route guidance

IRANS

26

7.3 Regulatory information

ISIS

 

Network Analyses

An analysis was performed of the network formed by the ATIS and the CVO–specific functional characteristics and the information flows that connect them. This analysis parallels that done for the private drivers.

Measure of centrality. Freeman's measures of centrality for functional characteristics of commercial drivers show differences in comparison to the analysis of the private drivers. For the commercial drivers, dispatch (9.2) appeared to be most central in terms of information received from other functional characteristics. Three functional characteristics all had the same measure of centrality, based on the information they provided to other functional characteristics; i.e., trip planning (5.1), pre–driver route and destination selection (5.3), and road condition information (8.2). Table 34 summarizes these results.

Table 34. Centrality measures for commercial driver functional characteristics.

FUNCTION

INPUT
CENTRALITY

OUTPUT
CENTRALITY

IRANS

5.1

20

48

 

5.2

20

32

 

5.3

32

48

 

5.4

44

28

 

5.5

12

0

 

5.6

40

8

 

5.7

0

24

 

5.8

32

44

IMSIS

6.1

20

12

 

6.2

12

20

 

6.3

36

8

 

6.4

24

12

ISIS

7.1

20

8

 

7.2

12

4

 

7.3

0

0

 

7.4

4

24

IVSAWS

8.1

8

16

 

8.2

16

48

 

8.3

8

20

 

8.4

16

24

 

8.5

0

40

 

8.6

0

40

CVO

9.1

52

8

 

9.2

68

20

 

9.3

40

16

 

9.4

28

12

MEAN

21.69

21.69

STANDARD DEVIATION

17.12

14.89

 

Cliques

Using the CVO functions, there was a possibility of 57 cliques containing 3 or more functions. Considering that a clique indicates that each function is immediately linked to the others in the clique, this measure becomes a very constrained way for functions to interact. Table 35 indicates the first 29 cliques in the analysis. Considering that quite a large number of cliques exist for the CVO, it is easy to select scenarios that would reflect some of these groups of functional characteristics.

Table 35. Cliques for commercial functions.

CLIQUE

FUNCTIONS

1

5.1

5.2

5.3

6.3

8.2

9.2

2

5.1

5.2

5.3

8.2

8.6

9.2

3

5.1

5.2

5.3

5.7

9.1

9.3

4

5.1

5.2

5.3

9.1

9.2

9.3

5

5.1

5.2

5.3

5.6

6.1

 

6

5.1

5.2

5.3

5.6

8.2

 

7

5.1

5.3

5.6

7.1

8.2

 

8

5.1

5.3

7.4

9.1

9.2

 

9

5.1

5.3

7.4

9.2

9.4

 

10

5.2

5.3

5.8

6.3

8.2

9.1

11

5.2

5.3

5.8

8.2

9.1

9.2

12

5.2

5.3

5.7

5.8

9.2

9.3

13

5.2

5.3

5.8

9.2

9.3

9.4

14

5.2

5.3

5.6

5.8

6.2

 

15

5.2

5.3

5.6

5.8

8.1

 

16

5.2

5.4

5.8

6.3

8.2

9.1

17

5.2

5.4

5.8

8.2

9.1

9.2

18

5.2

5.4

5.8

9.2

9.3

 

19

5.4

5.8

8.5

9.1

9.2

 

20

5.4

5.8

8.5

9.2

9.3

 

21

5.4

5.8

8.6

9.1

9.2

 

22

5.4

5.8

8.6

9.2

9.3

 

23

5.2

5.4

5.6

5.8

8.2

 

24

5.8

6.4

8.2

9.1

9.2

 

25

5.8

6.3

6.4

8.2

9.2

 

26

6.4

8.2

8.4

9.1

9.2

 

27

6.3

6.4

8.2

8.4

9.2

 

28

5.8

8.5

9.2

9.3

9.4

 

29

5.8

8.6

9.2

9.3

9.4

 

 

Clusters

The cluster analysis grouped the functions into five distinct clusters (see table 36). The five clusters for the commercial vehicle analysis are listed in table 37. The cluster analysis generated interesting results in the sense that except for one, each cluster organized functional characteristics into meaningful goals or sets of activities. These clusters did not correspond to the formal groupings of functional characteristics (IRANS, IMSIS, ISIS, IVSAWS, and CVO-specific) as closely as they did for the private-driver analysis. As a consequence, these findings suggest that it is important to attend closely to the CVO-specific functions as they tend to interact with the other functions in a way that alters the groupings found in the private applications.

Table 36. Clusters for commercial functions.

FUNCTION

9.1

5.8

5.3

8.2

6.4

6.3

9.2

7.2

7.1

5.4

8.1

5.6

5.7

5.2

9.3

5.1

9.4

7.3

5.5

7.4

8.3

6.1

6.2

8.5

8.6

8.4

9.1

1

1

1

1

1

       

1

     

1

 

1

     

1

1

   

1

1

1

5.8

 

1

1

1

1

             

1

1

               

1

1

1

 

5.3

 

1

1

1

   

1

         

1

1

 

1

     

1

   

1

     

8.2

 

1

1

1

         

1

         

1

                   

6.4

1

1

 

1

1

1

1

                                   

1

6.3

 

1

1

1

 

1

     

1

     

1

 

1

       

1

1

     

1

9.2

1

1

1

1

1

1

1

   

1

   

1

1

1

1

1

   

1

1

   

1

1

1

7.2

   

1

       

1

 

1

         

1

                   

7.1

   

1

1

       

1

1

1

       

1

                   

5.4

 

1

 

1

   

1

   

1

1

1

 

1

1

       

1

 

1

 

1

1

 

8.1

                   

1

                 

1

       

1

5.6

 

1

1

1

     

1

1

 

1

1

     

1

     

1

 

1

1

     

5.7

                       

1

                         

5.2

     

1

             

1

1

1

 

1

           

1

     

9.3

 

1

1

     

1

         

1

1

1

1

1

     

1

   

1

1

 

5.1

     

1

               

1

 

1

1

     

1

   

1

     

9.4

 

1

1

                   

1

1

1

1

           

1

1

 

7.3

                                 

1

               

5.5

   

1

         

1

1

               

1

             

7.4

                               

1

   

1

           

8.3

                                       

1

   

1

1

 

6.1

 

1

1

                       

1

         

1

 

1

1

 

6.2

                                           

1

1

1

1

8.5

                                             

1

   

8.6

                                               

1

 

8.4

     

1

           

1

                       

1

1

1

 

Table 37. Commercial vehicle cluster analysis.

CLUSTER 1: RESOURCE MANAGEMENT AND PLANNING

5.3 Pre–drive route and destination selection
5.8 Route scheduling
6.3 Destination coordination
6.4 Message transfer
8.2 Road condition information
9.1 Fleet resource management
9.2 Dispatch

IRANS
IRANS
IMSIS
IMSIS
IVSAWS
CVO–specific
CVO–specific

CLUSTER 2: NAVIGATION AND ROUTE GUIDANCE

5.4 Dynamic route selection
5.6 Route navigation
7.1 Guidance sign information
7.2 Notification information
8.1 Immediate hazard notification

IRANS
IRANS
ISIS
ISIS
IVSAWS

CLUSTER 3: REGULATORY AND ADMINISTRATIVE COORDINATION

5.1 Trip planning
5.2 Multi–mode travel coordination
5.7 Automatic toll collection
9.3 Regulatory administration
9.4 Regulatory enforcement

IRANS
IRANS
IRANS
CVO–specific
CVO–specific

CLUSTER 4: MISCELLANEOUS FUNCTIONS

This cluster was not meaningful. It was composed of four functions and each function was interacting only with itself; there were no interactions with any of the other functions.

CLUSTER 5: SERVICES REQUEST

6.1 Broadcast services/attractions
6.2 Services/attractions directory
8.4 Manual aid request
8.5 Vehicle condition monitoring
8.6 Cargo condition monitoring

IMSIS
IMSIS
IVSAWS
IVSAWS
IVSAWS

 

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