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Publication Number: FHWA-RD-97-106

Rural Public Transportation Technologies: User Needs and Applications FR1-798

Table 56. Accident Type Distribution by Ramp Segment Type for
Rural Diamond Off-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
20.4
0.3
 
70.6
0.0
0.0
 
0.0
0.0
0.0
0.0
0.0
-
 
-
 
-
21
1
 
162
-
-
 
-
-
-
-
-
155
 
0
 
0
6.2
0.3
 
47.8
-
-
 
-
-
-
-
-
45.7
 
0.0
 
0.0
2
0
 
2
-
-
 
-
-
-
-
-
2
 
0
 
0
0.6
0.0
 
7.1
-
-
 
-
-
-
-
-
0.6
 
0.0
 
0.0
5
0
 
24
-
-
 
-
-
-
-
-
3
 
0
 
0
1.5
0.0
 
7.1
-
-
 
-
-
-
-
-
0.9
 
0.0
 
0.0
0
0
 
6
-
-
 
-
-
-
-
-
5
 
0
 
0
0.0
0.0
 
1.8
-
-
 
-
-
-
-
-
1.5
 
0.0
 
0.0
7
0
 
32
-
-
 
-
-
-
-
-
10
 
0
 
0
2.1
0.0
 
9.4
-
-
 
-
-
-
-
-
3.0
 
0.0
 
0.0
Total 91.3 339 100.0 6 1.8 32 9.4 11 3.2 49 14.5

Conversion: 1 mi = 1.61 km

Table 56. Accident Type Distribution by Ramp Segment Type for
Rural Diamond Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
20.4
 
0.3
 
70.6
0.0
 
0.0
 
0.0
0.0
0.0
0.0
0.0
 
-
 
 
-
 
 
-
21
 
1
 
162
-
 
-
 
-
-
-
-
-
 
155
 
 
0
 
 
0
6.2
 
0.3
 
47.9
-
 
-
 
-
-
-
-
-
 
45.7
 
 
0.0
 
 
0.0
1
 
0
 
0
-
 
-
 
-
-
-
-
-
 
0
 
 
0
 
 
0
0.3
 
0.0
 
0.0
-
 
-
 
-
-
-
-
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
1
-
 
-
 
-
-
-
-
-
 
2
 
 
0
 
 
0
0.0
 
0.0
 
0.3
-
 
-
 
-
-
-
-
-
 
0.6
 
 
0.0
 
 
0.0
0
 
0
 
0
-
 
-
 
-
-
-
-
-
 
1
 
 
0
 
 
0
0.0
 
0.0
 
0.0
-
 
-
 
-
-
-
-
-
 
0.3
 
 
0.0
 
 
0.0
5
 
0
 
37
-
 
-
 
-
-
-
-
-
 
11
 
 
0
 
 
0
1.5
 
0.0
 
10.9
-
 
-
 
-
-
-
-
-
 
3.2
 
 
0.0
 
 
0.0
0
 
0
 
8
-
 
-
 
-
-
-
-
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
2.4
-
 
-
 
-
-
-
-
-
 
0.0
 
 
0.0
 
 
0.0
6
 
0
 
46
-
 
-
 
-
-
-
-
-
 
14
 
 
0
 
 
0
1.8
 
0.0
 
13.6
-
 
-
 
-
-
-
-
-
 
4.1
 
 
0.0
 
 
0.0
Total 91.3 339 100.0 1 0.3 3 0.9 1 0.3 53 15.6 8 2.4 66 19.5

Conversion: 1 mi = 1.61 km

Table 56. Accident Type Distribution by Ramp Segment Type for
Rural Diamond Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
20.4
 
0.3
 
 
70.6
0.0
 
0.0
 
 
0.0
 
0.0
0.0
0.0
 
0.0
 
-
 
 
-
 
 
-
21
 
1
 
 
162
-
 
-
 
 
-
 
-
-
-
 
-
 
155
 
 
0
 
 
0
6.2
 
0.3
 
 
47.8
-
 
-
 
 
-
 
-
-
-
 
-
 
45.7
 
 
0.0
 
 
0.0
0
 
0
 
 
1
-
 
-
 
 
-
 
-
-
-
 
-
 
0
 
 
0
 
 
-
0.0
 
0.0
 
 
0.3
-
 
-
 
 
-
 
-
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
-
-
-
 
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
-
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
2
 
1
 
 
43
-
 
-
 
 
-
 
-
-
-
 
-
 
53
 
 
0
 
 
0
0.6
 
0.3
 
 
12.7
-
 
-
 
 
-
 
-
-
-
 
-
 
15.6
 
 
0.0
 
 
0.0
5
 
0
 
 
30
-
 
-
 
 
-
 
-
-
-
 
-
 
16
 
 
0
 
 
0
1.5
 
0.0
 
 
8.9
-
 
-
 
 


-
-
-
 
-
 
4.7
 
 
0.0
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
-
-
-
 
-
 
23
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
-
-
-
 
-
 
6.8
 
 
0.0
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
-
-
-
 
-
 
33
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
-
-
-
 
-
 
9.7
 
 
0.0
 
 
0.0
1
 
0
 
 
10
-
 
-
 
 
-
 
-
-
-
 
-
 
6
 
 
0
 
 
0
0.3
 
0.0
 
 
3.0
-
 
-
 
 
-
 
-
-
-
 
-
 
1.8
 
 
0.0
 
 
0.0
8
 
1
 
 
84
-
 
-
 
 
-
 
-
-
-
 
-
 
131
 
 
0
 
 
0
2.4
 
0.3
 
 
24.8
-
 
-
 
 
-
 
-
-
-
 
-
 
38.6
 
 
0.0
 
 
0.0
Total 91.3 339 100.0 1 0.3 0 0.0 99 29.2 51 15.0 23 6.8 33 9.7 17 5.0 224 66.1

Conversion: 1 mi = 1.61 km

Table 57. Accident Type Distribution by Ramp Segment Type for
Rural Diamond On-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
0.0
0.0
 
36.6
47.8
0.4
 
0.0
0.0
0.0
0.0
0.0
-
 
-
 
-
-
-
 
10
69
-
 
-
-
-
-
-
64
 
0
 
0
-
-
 
7.0
-
-
 
-
-
-
-
-
44.8
 
0.0
 
0.0
-
-
 
0
4
-
 
-
-
-
-
-
0
 
0
 
0
-
-
 
0.0
2.8
-
 
-
-
-
-
-
0.0
 
0.0
 
0.0
-
-
 
10
-
-
 
-
-
-
-
-
3
 
0
 
0
-
-
 
0.0
7.0
-
 
-
-
-
-
-
0.0
 
0.0
 
0.0
-
-
 
0
3
-
 
-
-
-
-
-
0
 
0
 
0
-
-
 
0.0
2.1
-
 
-
-
-
-
-
0.0
 
0.0
 
0.0
-
-
 
0
17
-
 
-
-
-
-
-
3
 
0
 
0
-
-
 
0.0
11.9
-
 
-
-
-
-
-
2.1
 
0.0
 
0.0
Total 84.8 143 100.0 4 2.8 13 9.1 3 2.1 20 14.0

Conversion: 1 mi = 1.61 km

Table 57. Accident Type Distribution by Ramp Segment Type for
Rural Diamond On-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
0.0
 
0.0
 
36.6
47.8
 
0.4
 
0.0
0.0
0.0
0.0
0.0
 
-
 
 
-
 
 
-
-
 
-
 
10
69
 
-
 
-
-
-
-
-
 
64
 
 
0
 
 
0
-
 
-
 
7.0
48.3
 
-
 
-
-
-
-
-
 
44.8
 
 
0.0
 
 
0.0
-
 
-
 
0
1
 
-
 
-
-
-
-
-
 
0
 
 
0
 
 
0
-
 
-
 
0.0
0.7
 
-
 
-
-
-
-
-
 
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
-
 
-
 
0.0
0.0
 
-
 
-
-
-
-
-
 
0.0
 
 
0.0
 
 
0.0
-
 
-
 
2
11
 
-
 
-
-
-
-
-
 
14
 
 
0
 
 
0
-
 
-
 
1.4
7.7
 
-
 
-
-
-
-
-
 
9.8
 
 
0.0
 
 
0.0
-
 
-
 
2
0
 
-
 
-
-
-
-
-
 
0
 
 
0
 
 
0
-
 
-
 
1.4
0.0
 
-
 
-
-
-
-
-
 
0.0
 
 
0.0
 
 
0.0
-
 
-
 
4
12
 
-
 
-
-
-
-
-
 
14
 
 
0
 
 
0
-
 
-
 
2.8
8.4
 
-
 
-
-
-
-
-
 
9.8
 
 
0.0
 
 
0.0
Total 84.8 143 100.0 1 0.7 0 0.0 0 0.0 27 18.9 2 1.4 30 21.0

Conversion: 1 mi = 1.61 km

Table 57. Accident Type Distribution by Ramp Segment Type for
Rural Diamond On-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
0.0
 
0.0
 
 
36.6
0.4
 
0.0
 
 
0.0
 
0.0
0.0
0.0
 
0.0
 
-
 
 
-
 
 
-
-
 
-
 
 
10
69
 
-
 
 
-
 
-
-
-
 
-
 
64
 
 
0
 
 
0
-
 
-
 
 
7.0
48.3
 
-
 
 
-
 
-
-
-
 
-
 
44.8
 
 
0.0
 
 
0.0
-
 
-
 
 
0
0
 
-
 
 
-
 
-
-
-
 
-
 
0
 
 
0
 
 
-
-
 
-
 
 
0.0
0.0
 
-
 
 
-
 
-
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
-
 
-
 
 
0
1
 
-
 
 
-
 
-
-
-
 
-
 
0
 
 
0
 
 
0
-
 
-
 
 
0.0
0.7
 
-
 
 
-
 
-
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
-
 
-
 
 
3
18
 
-
 
 
-
 
-
-
-
 
-
 
2
 
 
0
 
 
0
-
 
-
 
 
2.1
12.6
 
-
 
 
-
 
-
-
-
 
-
 
1.4
 
 
0.0
 
 
0.0
-
 
-
 
 
3
17
 
-
 
 
-
 
-
-
-
 
-
 
6
 
 
0
 
 
0
-
 
-
 
 
2.1
11.9
 
-
 
 


-
-
-
 
-
 
4.2
 
 
0.0
 
 
0.0
-
 
-
 
 
0
0
 
-
 
 
-
 
-
-
-
 
-
 
3
 
 
0
 
 
0
-
 
-
 
 
0.0
0.0
 
-
 
 
-
 
-
-
-
 
-
 
2.1
 
 
0.0
 
 
0.0
-
 
-
 
 
0
0
 
-
 
 
-
 
-
-
-
 
-
 
36
 
 
0
 
 
0
-
 
-
 
 
0.0
0.0
 
-
 
 
-
 
-
-
-
 
-
 
25.2
 
 
0.0
 
 
0.0
-
 
-
 
 
0
4
 
-
 
 
-
 
-
-
-
 
-
 
0
 
 
0
 
 
0
-
 
-
 
 
0.0
2.8
 
-
 
 
-
 
-
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
-
 
-
 
 
6
40
 
-
 
 
-
 
-
-
-
 
-
 
47
 
 
0
 
 
0
-
 
-
 
 
4.2
28.0
 
-
 
 
-
 
-
-
-
 
-
 
32.9
 
 
0.0
 
 
0.0
Total 84.8 143 100.0 0 0.0 1 0.7 23 16.1 26 18.2 3 2.1 36 25.2 4 2.8 93 65.0

Conversion: 1 mi = 1.61 km

Table 58. Accident Type Distribution by Ramp Segment Type for
Urban Diamond Off-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
13.7
1.2
 
32.7
0.0
0.0
 
0.0
0.0
0.0
0.0
0.0
-
 
-
 
-
130
43
 
823
-
-
 
-
2
-
-
-
717
 
0
 
0
7.6
2.5
 
47.9
-
-
 
-
0.1
-
-
-
41.7
 
0.0
 
0.0
0
0
 
9
-
-
 
-
0
-
-
-
1
 
0
 
0
0.0
0.0
 
0.5
-
-
 
-
0.0
-
-
-
0.1
 
0.0
 
0.0
7
0
 
23
-
-
 
-
0
-
-
-
2
 
0
 
0
0.4
0.0
 
1.3
-
-
 
-
0.0
-
-
-
0.1
 
0.0
 
0.0
2
0
 
11
-
-
 
-
0
-
-
-
4
 
0
 
0
0.1
0.0
 
0.6
-
-
 
-
0.0
-
-
-
0.2
 
0.0
 
0.0
9
0
 
43
-
-
 
-
0
-
-
-
7
 
0
 
0
0.5
0.0
 
2.5
-
-
 
-
0.0
-
-
-
0.4
 
0.0
 
0.0
Total 47.6 1,719 100.0 10 0.6 32 1.9 17 1.0 59 3.4

Conversion: 1 mi = 1.61 km

Table 58. Accident Type Distribution by Ramp Segment Type for
Urban Diamond Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
13.7
 
1.2
 
32.7
0.0
 
0.0
 
0.0
0.0
0.0
0.0
0.0
 
-
 
 
-
 
 
-
130
 
43
 
823
-
 
-
 
-
2
-
-
-
 
717
 
 
0
 
 
0
7.5
 
2.5
 
47.9
-
 
-
 
-
0.1
-
-
-
 
41.7
 
 
0.0
 
 
0.0
0
 
0
 
0
-
 
-
 
-
0
-
-
-
 
1
 
 
0
 
 
0
0.0
 
0.0
 
0.0
-
 
-
 
-
0.0
-
-
-
 
0.1
 
 
0.0
 
 
0.0
1
 
1
 
5
-
 
-
 
-
0
-
-
-
 
2
 
 
0
 
 
0
0.1
 
0.1
 
0.3
-
 
-
 
-
0.0
-
-
-
 
0.1
 
 
0.0
 
 
0.0
0
 
0
 
2
-
 
-
 
-
0
-
-
-
 
3
 
 
0
 
 
0
0.0
 
0.0
 
0.1
-
 
-
 
-
0.0
-
-
-
 
0.2
 
 
0.0
 
 
0.0
15
 
3
 
66
-
 
-
 
-
2
-
-
-
 
18
 
 
0
 
 
0
0.9
 
0.2
 
3.8
-
 
-
 
-
0.1
-
-
-
 
1.0
 
 
0.0
 
 
0.0
0
 
0
 
4
-
 
-
 
-
0
-
-
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.2
-
 
-
 
-
0.0
-
-
-
 
0.0
 
 
0.0
 
 
0.0
16
 
4
 
77
-
 
-
 
-
2
-
-
-
 
24
 
 
0
 
 
0
0.9
 
0.2
 
4.5
-
 
-
 
-
0.1
-
-
-
 
1.4
 
 
0.0
 
 
0.0
Total 47.6 1,719 100.0 1 0.1 9 0.5 5 0.3 104 6.1 4 0.2 123 7.2

Conversion: 1 mi = 1.61 km

Table 58. Accident Type Distribution by Ramp Segment Type for
Urban Diamond Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
13.7
 
1.2
 
 
32.7
0.0
 
0.0
 
 
0.0
 
0.0
0.0
0.0
 
0.0
 
-
 
 
-
 
 
-
130
 
43
 
 
823
-
 
-
 
 
-
 
2
-
-
 
-
 
717
 
 
4
 
 
0
7.6
 
2.5
 
 
47.9
-
 
-
 
 
-
 
0.1
-
-
 
-
 
41.7
 
 
0.2
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
0
-
-
 
-
 
0
 
 
0
 
 
-
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
0.0
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
83
 
0
 
 
2
-
 
-
 
 
-
 
0
-
-
 
-
 
0
 
 
0
 
 
0
0
 
0.0
 
 
0.1
-
 
-
 
 
-
 
0.0
-
-
 
-
 
0.0
 
 
0.0
 
 
0.0
0.0
 
25
 
 
451
-
 
-
 
 
-
 
0
-
-
 
-
 
356
 
 
3
 
 
0
4.8
 
1.5
 
 
26.2
-
 
-
 
 
-
 
0.0
-
-
 
-
 
20.7
 
 
0.2
 
 
0.0
18
 
14
 
 
196
-
 
-
 
 
-
 
0
-
-
 
-
 
57
 
 
1
 
 
0
1.0
 
0.8
 
 
11.4
-
 
-
 
 
-
 
0.0
-
-
 
-
 
3.3
 
 
0.1
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
0
-
-
 
-
 
100
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
0.0
-
-
 
-
 
5.8
 
 
0.0
 
 
0.0
0
 
0
 
 
0
-
 
-
 
 
-
 
0
-
-
 
-
 
163
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
-
 
-
 
 
-
 
0.0
-
-
 
-
 
9.5
 
 
0.0
 
 
0.0
4
 
0
 
 
54
-
 
-
 
 
-
 
0
-
-
 
-
 
10
 
 
0
 
 
0
0.2
 
0.0
 
 
3.1
-
 
-
 
 
-
 
0.0
-
-
 
-
 
0.6
 
 
0.0
 
 
0.0
105
 
39
 
 
703
-
 
-
 
 
-
 
0
-
-
 
-
 
686
 
 
4
 
 
0
6.1
 
2.3
 
 
40.9
-
 
-
 
 
-
 
0.0
-
-
 
-
 
39.9
 
 
0.2
 
 
0.0
Total 47.6 1,719 100.0 0 0.0 2 0.1 918 53.4 286 16.6 100 5.8 163 9.5 68 4.0 1,537 69.4

Conversion: 1 mi = 1.61 km

Table 59. Accident Type Distribution by Ramp Segment Type for
Urban Parclo Loop Off-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
0.4
0.0
 
0.8
0.0
0.0
 
0.1
0.0
0.0
0.0
0.6
-
 
-
 
-
7
-
 
32
-
-
 
0
-
-
-
11
59
 
0
 
0
6.4
-
 
29.4
-
-
 
0.0
-
-
-
10.1
54.1
 
0.0
 
0.0
0
-
 
0
-
-
 
0
-
-
-
1
1
 
0
 
0
0.0
-
 
0.0
-
-
 
0.0
-
-
-
0.9
0.9
 
0.0
 
0.0
2
-
 
2
-
-
 
0
-
-
-
0
0
 
0
 
0
1.8
-
 
1.8
-
-
 
0.0
-
-
-
0.0
0.0
 
0.0
 
0.0
1
-
 
1
-
-
 
0
-
-
-
0
0
 
0
 
0
0.9
-
 
0.9
-
-
 
0.0
-
-
-
0.0
0.0
 
0.0
 
0.0
3
0
 
3
-
-
 
0
-
-
-
1
1
 
0
 
0
2.8
-
 
2.8
-
-
 
0.0
-
-
-
0.9
0.9
 
0.0
 
0.0
Total 1.9 109 100.0 2 1.8 4 3.7 2 1.8 8 7.3

Conversion: 1 mi = 1.61 km

Table 59. Accident Type Distribution by Ramp Segment Type for
Urban Parclo Loop Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
0.4
 
0.0
 
0.8
0.0
 
0.0
 
0.1
0.0
0.0
0.0
0.0
 
-
 
 
-
 
 
-
7
 
-
 
32
-
 
-
 
0
-
-
-
11
 
59
 
 
0
 
 
0
6.4
 
-
 
29.4
-
 
-
 
0.0
-
-
-
10.1
 
54.1
 
 
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
-
 
-
 
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
0.0
 
-
 
0.0
-
 
-
 
0.0
-
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
3
 
-
 
3
-
 
-
 
0
-
-
-
1
 
1
 
 
0
 
 
0
2.8
 
-
 
2.8
-
 
-
 
0.0
-
-
-
0.9
 
0.9
 
 
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
3
 
-
 
3
-
 
-
 
0
-
-
-
1
 
1
 
 
0
 
 
0
2.8
 
-
 
2.8
-
 
-
 
0.0
-
-
-
0.9
 
0.9
 
 
0.0
 
 
0.0
Total 1.9 109 100.0 0 0.0 0 0.0 0 0.0 8 7.3 0 0.0 8 7.3

Conversion: 1 mi = 1.61 km

Table 59. Accident Type Distribution by Ramp Segment Type for
Urban Parclo Loop Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
0.4
 
0.0
 
 
0.8
0.0
 
0.0
 
 
0.1
 
0.0
0.0
0.0
 
0.6
 
-
 
 
-
 
 
-
7
 
-
 
 
32
-
 
-
 
 
0
 
-
-
-
 
11
 
59
 
 
0
 
 
0
6.4
 
-
 
 
29.4
-
 
-
 
 
0.0
 
-
-
-
 
10.1
 
54.1
 
 
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
 
-
-
-
 
-
 
0
 
 
0
 
 
0
0.0
 
-
 
 
0.0
-
 
-
 
 
0.0
 
-
-
-
 
0
 
0.0
 
 
0.0
 
 
0.0
0
 
-
 
 
22
-
 
-
 
 
0
 
-
-
-
 
0.0
 
37
 
 
0
 
 
0
0.0
 
-
 
 
20.2
-
 
-
 
 
0.0
 
-
-
-
 
7
 
33.9
 
 
0.0
 
 
0.0
0
 
-
 
 
2
-
 
-
 
 
0
 
-
-
-
 
6.4
 
1
 
 
0
 
 
0
0.0
 
-
 
 
1.8
-
 
-
 
 
0.0 

-
-
-
 
2
 
0.9
 
 
0.0
 
 
0.0
0
 
-
 
 
0
-
 
-
 
 
0
 
-
-
-
 
1.8
 
16
 
 
0
 
 
0
0.0
 
-
 
 
0.0
-
 
-
 
 
0.0
 
-
-
-
 
0
 
14.7
 
 
0.0
 
 
0.0
0
 
-
 
 
0
-
 
-
 
 
0
 
-
-
-
 
0
 
3
 
 
0
 
 
0
0.0
 
-
 
 
0.0
-
 
-
 
 
0.0
 
-
-
-
 
0.0
 
2.8
 
 
0.0
 
 
0.0
1
 
-
 
 
2
-
 
-
 
 
0
 
-
-
-
 
0
 
0
 
 
0
 
 
0
0.9
 
-
 
 
1.8
-
 
-
 
 
0.0
 
-
-
-
 
0.0
 
0.0
 
 
0.0
 
 
0.0
1
 
-
 
 
26
-
 
-
 
 
0
 
-
-
-
 
9
 
57
 
 
0
 
 
0
0.9
 
-
 
 
23.9
-
 
-
 
 
0.0
 
-
-
-
 
8.3
 
52.3
 
 
0.0
 
 
0.0
Total 1.9 109 100.0 0 0.0 0 0.0 66 60.6 5 4.6 16 14.7 3 2.8 3 2.8 93 85.3

Conversion: 1 mi = 1.61 km

Table 60. Accident Type Distribution by Ramp Segment Type for
Urban Free-Flow Off-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
1.0
0.1
 
6.8
0.8
0.0
 
0.2
0.0
0.0
0.0
0.2
-
 
-
 
-
16
0
 
124
18
-
 
11
1
-
-
13
0
 
101
 
0
5.6
0.0
 
43.7
6.3
-
 
3.9
0.4
-
-
4.6
0.0
 
35.6
 
0.0
1
0
 
2
0
-
 
0
0
-
-
0
0
 
0
 
0
0.4
0.0
 
0.7
0.0
-
 
0.0
0.0
-
-
0.0
0.0
 
0.0
 
0.0
3
0
 
15
0
-
 
0
1
-
-
0
0
 
0
 
0
1.1
0.0
 
5.3
0.0
-
 
0.0
0.4
-
-
0.0
0.0
 
0.0
 
0.0
0
0
 
2
0
-
 
0
0
-
-
0
0
 
0
 
0
0.0
0.0
 
0.7
0.0
-
 
0.0
0.0
-
-
0.0
0.0
 
0.0
 
0.0
4
0
 
19
0
-
 
0
1
-
-
0
0
 
0
 
0
1.4
0.0
 
6.7
0.0
-
 
0.0
0.4
-
-
0.0
0.0
 
0.0
 
0.0
Total 8.9 284 100.0 3 1.1 19 6.7 2 0.7 24 8.5

Conversion: 1 mi = 1.61 km

Table 60. Accident Type Distribution by Ramp Segment Type for
Urban Free-Flow Loop Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
1.0
 
0.1
 
6.8
0.8
 
0.0
 
0.2
0.0
0.0
0.0
0.2
 
-
 
 
-
 
 
-
16
 
0
 
124
18
 
-
 
11
1
-
-
13
 
0
 
 
101
 
 
0
5.6
 
0.0
 
43.7
6.3
 
-
 
3.9
0.4
-
-
4.6
 
0.0
 
 
35.6
 
 
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
 
0.0
 
 
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
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
2
0
 
-
 
0
0
-
-
0
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.7
0.0
 
-
 
0.0
0.0
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
10
 
0
 
29
1
 
-
 
1
0
-
-
0
 
0
 
 
3
 
 
0
3.5
 
0.0
 
10.2
0.4
 
-
 
0.4
0.0
-
-
0.0
 
0.0
 
 
1.1
 
 
0.0
0
 
0
 
1
0
 
-
 
0
0
-
-
0
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.4
0.0
 
-
 
0.0
0.0
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
10
 
0
 
32
1
 
-
 
1
0
-
-
0
 
0
 
 
3
 
 
0
3.5
 
0.0
 
11.3
0.4
 
-
 
0.4
0.0
-
-
0.0
 
0.0
 
 
1.1
 
 
0.0
Total 8.9 284 100.0 0 0.0 0 0.0 2 0.7 45 15.8 1 0.4 48 16.9

Conversion: 1 mi = 1.61 km

Table 60. Accident Type Distribution by Ramp Segment Type for
Urban Free-Flow Loop Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
1.0
 
0.1
 
 
6.8
0.8
 
0.0
 
 
0.0
 
0.0
0.0
0.0
 
0.0
 
-
 
 
-
 
 
-
16
 
0
 
 
124
18
 
-
 
 
11
 
1
-
-
 
13
 
0
 
 
101
 
 
0
5.6
 
0.0
 
 
43.7
6.3
 
-
 
 
3.9
 
0.4
-
-
 
4.6
 
0.0
 
 
35.6
 
 
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
 
0.0
 
 
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-
-
-
 
0.0
 
0.0
 
 
0.0
 
 
0.0
1
 
0
 
 
52
12
 
-
 
 
7
 
0
-
-
 
10
 
0
 
 
89
 
 
0
0.4
 
0.0
 
 
18.3
4.2
 
-
 
 
2.5
 
0.0
-
-
 
3.5
 
0.0
 
 
31.3
 
 
0.0
1
 
0
 
 
21
5
 
-
 
 
3
 
0
-
-
 
1
 
0
 
 
8
 
 
0
0.4
 
0.0
 
 
7.4
1.8
 
-
 
 
1.1 

0.0
-
-
 
0.4
 
0.0
 
 
2.8
 
 
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
 
0.0
 
 
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
-
-
 
0.0
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
 
0
1
 
-
 
 
0
 
0
-
-
 
1
 
0
 
 
1
 
 
0
0.0
 
0.0
 
 
0.0
0.4
 
-
 
 
0.0
 
0.0
-
-
 
0.4
 
0.0
 
 
0.4
 
 
0.0
2
 
0
 
 
73
12
 
-
 
 
10
 
0
-
-
 
12
 
0
 
 
98
 
 
0
0.7
 
0.0
 
 
25.7
4.2
 
-
 
 
3.5
 
0.0
-
-
 
4.2
 
0.0
 
 
34.5
 
 
0.0
Total 8.9 284 100.0 0 0.0 0 0.0 171 60.2 39 13.7 0 0.0 0 0.0 2 0.7 212 74.6

Conversion: 1 mi = 1.61 km

Table 61. Accident Type Distribution by Ramp Segment Type for
Urban Outer Connection Off-Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.0
0.1
 
9.9
1.1
0.1
 
0.0
0.0
0.0
0.0
1.8
-
 
-
 
-
24
0
 
334
7
6
 
-
10
-
-
41
131
 
144
 
0
3.4
0.0
 
47.9
1.0
0.9
 
-
1.4
-
-
5.9
18.8
 
20.7
 
0.0
0
0
 
5
0
0
 
-
0
-
-
0
0
 
0
 
0
0.0
0.0
 
0.7
0.0
0.0
 
-
0.0
-
-
0.0
0.0
 
0.0
 
0.0
0
0
 
25
0
0
 
-
2
-
-
1
0
 
1
 
0
0.0
0.0
 
3.6
0.0
0.0
 
-
0.3
-
-
0.1
0.0
 
0.1
 
0.0
0
0
 
3
0
0
 
-
1
-
-
0
1
 
0
 
0
0.0
0.0
 
0.4
0.0
0.0
 
-
0.1
-
-
0.0
0.1
 
0.0
 
0.0
0
0
 
33
0
0
 
-
3
-
-
1
1
 
1
 
0
0.0
0.0
 
4.7
0.0
0.0
 
-
0.4
-
-
0.1
0.1
 
0.1
 
0.0
Total 15.9 697 100.0 5 0.7 29 4.2 5 0.7 39 5.6

Conversion: 1 mi = 1.61 km

Table 61. Accident Type Distribution by Ramp Segment Type for
Urban Connection Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.0
 
0.1
 
9.9
1.1
 
0.1
 
0.0
0.0
0.0
0.0
1.8
 
-
 
 
-
 
 
-
24
 
0
 
334
7
 
6
 
-
10
-
-
41
 
131
 
 
144
 
 
0
3.4
 
0.0
 
47.9
1.0
 
0.9
 
-
1.4
-
-
5.9
 
18.8
 
 
20.7
 
 
0.0
0
 
0
 
1
0
 
0
 
-
0
-
-
0
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.1
0.0
 
0.0
 
-
0.0
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
4
0
 
0
 
-
0
-
-
0
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.6
0.0
 
0.0
 
-
0.0
-
-
0.0
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
1
0
 
0
 
-
0
-
-
0
 
1
 
 
0
 
 
0
0.0
 
0.0
 
0.1
0.0
 
0.0
 
-
0.0
-
-
0.0
 
0.1
 
 
0.0
 
 
0.0
2
 
0
 
55
1
 
1
 
-
5
-
-
0
 
2
 
 
3
 
 
0
0.3
 
0.0
 
7.9
0.1
 
0.1
 
-
0.7
-
-
0.0
 
0.3
 
 
0.4
 
 
0.0
0
 
0
 
1
0
 
0
 
-
0
-
-
0
 
1
 
 
0
 
 
0
0.0
 
0.0
 
0.1
0.0
 
0.0
 
-
0.0
-
-
0.0
 
0.1
 
 
0.0
 
 
0.0
2
 
0
 
62
1
 
5
 
-
5
-
-
0
 
4
 
 
3
 
 
0
0.3
 
0.0
 
8.9
0.1
 
0.7
 
-
0.7
-
-
0.0
 
0.6
 
 
0.4
 
 
0.0
Total 15.9 697 100.0 1 0.1 4 0.6 2 0.3 69 9.9 2 0.3 78 11.2

Conversion: 1 mi = 1.61 km

Table 61. Accident Type Distribution by Ramp Segment Type for
Outer Connection Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
3.0
 
0.1
 
 
9.9
1.1
 
0.1
 
 
0.0
 
0.0
0.0
0.0
 
1.8
 
-
 
 
-
 
 
-
241
 
0
 
 
334
7
 
6
 
 
-
 
10
-
-
 
41
 
131
 
 
144
 
 
0
3.4
 
0.0
 
 
47.9
1.0
 
0.9
 
 
-
 
1.4
-
-
 
5.9
 
18.8
 
 
20.7
 
 
0.0
0
 
0
 
 
1
0
 
0
 
 
-
 
0
-
-
 
0
 
0
 
 
0
 
 
0
0.0
 
0.0
 
 
0.1
0.0
 
0.0
 
 
-
 
0.0
-
-
 
0.0
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
 
1
0
 
0
 
 
-
 
0
-
-
 
0
 
0
 
 
1
 
 
0
0.0
 
0.0
 
 
0.1
0.0
 
0.0
 
 
-
 
0.0
-
-
 
0.0
 
0.0
 
 
0.1
 
 
0.0
16
 
0
 
 
152
4
 
4
 
 
-
 
1
-
-
 
23
 
55
 
 
120
 
 
0
2.3
 
0.0
 
 
21.8
0.6
 
0.6
 
 
-
 
0.1
-
-
 
3.3
 
7.9
 
 
17.2
 
 
0.0
5
 
0
 
 
74
2
 
1
 
 
-
 
1
-
-
 
14
 
6
 
 
19
 
 
0
0.7
 
0.0
 
 
10.6
0.3
 
0.1
 
 


0.1
-
-
 
2.0
 
0.9
 
 
2.7
 
 
0.0
0
 
0
 
 
0
0
 
0
 
 
-
 
0
-
-
 
0
 
13
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
0.0
 
0.0
 
 
-
 
0.0
-
-
 
0.0
 
1.9
 
 
0.0
 
 
0.0
0
 
0
 
 
0
0
 
0
 
 
-
 
0
-
-
 
0
 
50
 
 
0
 
 
0
0.0
 
0.0
 
 
0.0
0.0
 
0.0
 
 
-
 
0.0
-
-
 
0.0
 
7.2
 
 
0.0
 
 
0.0
1
 
0
 
 
11
0
 
0
 
 
-
 
0
-
-
 
3
 
2
 
 
0
 
 
0
0.1
 
0.0
 
 
1.6
0.0
 
0.0
 
 
-
 
0.0
-
-
 
0.4
 
0.3
 
 
0.0
 
 
0.0
22
 
0
 
 
239
6
 
5
 
 
-
 
2
-
-
 
40
 
126
 
 
140
 
 
0
3.2
 
0.0
 
 
34.3
0.9
 
0.7
 
 
-
 
0.3
-
-
 
5.7
 
18.1
 
 
20.1
 
 
0.0
Total 15.9 697 100.0 1 0.1 2 0.3 375 53.8 122 17.5 13 1.9 50 7.2 17 2.4 580 83.2

Conversion: 1 mi = 1.61 km

Table 62. Accident Type Distribution by Ramp Segment Type for
Urban Direct and Semi-Direct Connection Ramps (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.5
1.4
 
16.5
7.6
2.4
 
0.2
1.3
1.9
0.0
0.0
-
 
-
 
-
29
9
 
305
71
21
 
2
41
33
1
-
5
 
30
 
0
5.3
1.6
 
55.8
13.0
3.8
 
0.4
7.5
6.0
0.2
-
0.9
 
5.5
 
0.0
0
0
 
11
1
0
 
0
0
3
0
-
0
 
0
 
0
0.0
0.0
 
2.0
0.2
0.0
 
0.0
0.0
0.5
0.0
-
0.0
 
0.0
 
0.0
2
0
 
43
2
0
 
0
6
5
1
-
0
 
0
 
0
0.4
0.0
 
7.9
0.4
0.0
 
0.0
1.1
0.9
0.2
-
0.0
 
0.0
 
0.0
2
0
 
3
0
0
 
0
0
0
0
-
0
 
0
 
0
0.4
0.0
 
0.5
0.0
0.0
 
0.0
0.0
0.0
0.0
-
0.0
 
0.0
 
0.0
4
0
 
57
3
0
 
0
0
8
1
-
0
 
0
 
0
0.7
0.0
 
10.4
0.5
0.0
 
0.0
0.0
1.5
0.2
-
0.0
 
0.0
 
0.0
Total 34.7 547 100.0 15 2.7 59 10.8 5 0.9 79 14.4

Conversion: 1 mi = 1.61 km

Table 62. Accident Type Distribution by Ramp Segment Type for
Urban Direct and Semi-Direct Connection Off-Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.5
 
1.4
 
16.5
7.6
 
2.4
 
0.2
1.3
1.9
0.0
0.0
 
-
 
 
-
 
 
-
29
 
9
 
305
71
 
21
 
2
41
33
1
-
 
5
 
 
30
 
 
0
5.3
 
1.6
 
55.8
13.0
 
3.8
 
0.4
7.5
6.0
0.2
-
 
0.9
 
 
5.5
 
 
0.0
0
 
0
 
1
0
 
0
 
0
0
0
0
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.2
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
-
 
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
0
 
0
 
0
0
 
0
 
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
-
 
0.0
 
 
0.2
 
 
0.0
9
 
1
 
137
8
 
8
 
0
23
12
0
-
 
1
 
 
2
 
 
0
1.6
 
0.2
 
25.0
1.5
 
1.5
 
0.0
4.2
2.2
0.0
-
 
0.2
 
 
0.4
 
 
0.0
0
 
0
 
2
1
 
0
 
0
0
1
0
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.4
0.2
 
0.0
 
0.0
0.0
0.2
0.0
-
 
0.0
 
 
0.0
 
 
0.0
9
 
1
 
140
9
 
8
 
0
24
13
0
-
 
1
 
 
3
 
 
0
1.6
 
0.2
 
25.6
1.6
 
1.5
 
0.0
2.4
2.4
0.0
-
 
0.2
 
 
0.5
 
 
0.0
Total 34.7 547 100.0 2 0.4 0 0.0 1 0.2 201 36.7 4 0.7 208 38.0

Conversion: 1 mi = 1.61 km

Table 62. Accident Type Distribution by Ramp Segment Type for
Urban Direct and Semi-Direct Connection Ramps (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
3.5
 
1.4
 
 
16.5
7.6
 
2.4
 
 
0.2
 
1.3
1.9
0.0
 
0.0
 
-
 
 
-
 
 
-
29
 
9
 
 
305
71
 
21
 
 
2
 
41
33
1
 
-
 
5
 
 
30
 
 
0
5.3
 
1.6
 
 
55.8
13.0
 
3.8
 
 
0.4
 
7.5
6.0
0.2
 
-
 
0.9
 
 
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
 
0.0
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
 
 
0.0
0.0
 
0.0
 
 
0.0
 
0.0
0.0
.0
 
-
 
0.0
 
 
0.0
 
 
0.0
6
 
4
 
 
66
38
 
7
 
 
1
 
10
8
0
 
-
 
2
 
 
20
 
 
0
1.1
 
0.7
 
 
12.1
6.9
 
1.3
 
 
0.2
 
1.8
1.5
0.0
 
-
 
0.4
 
 
3.7
 
 
0.0
9
 
3
 
 
39
21
 
5
 
 
1
 
1
3
0
 
-
 
1
 
 
6
 
 
0
1.6
 
0.5
 
 
7.1
3.8
 
0.9
 
 
0.2 

0.2
0.5
0.0
 
-
 
0.2
 
 
1.1
 
 
0.0
0
 
0
 
 
0
0
 
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
 
-
 
0.2
 
 
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
 
 
0.0
 
0.0
0.0
0.0
 
-
 
0.0
 
 
0.0
 
 
0.0
1
 
1
 
 
3
0
 
1
 
 
0
 
0
1
0
 
-
 
0
 
 
1
 
 
0
0.2
 
0.2
 
 
0.5
0.0
 
0.2
 
 
0.0
 
0.0
0.2
0.0
 
-
 
0.0
 
 
0.2
 
 
0.0
16
 
8
 
 
108
59
 
13
 
 
2
 
11
12
0
 
-
 
4
 
 
27
 
 
0
2.9
 
1.5
 
 
19.7
10.8
 
2.4
 
 
0.4
 
2.0
2.2
0.0
 
-
 
0.7
 
 
4.9
 
 
0.0
Total 34.7 547 100.0 0 0.0 0 0.0 162 29.6 89 16.3 1 0.2 0 0.0 8 1.5 260 47.5

Conversion: 1 mi = 1.61 km

Table 63. Accident Type Distribution by Ramp Segment Type for
Urban C/D Roads (1993 Through 1995)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Ran off road Overturned Other Total
Frequency (%) Frequency (%) Frequency (%) Frequency (%) Frequency (%)
Normal deceleration lane
Deceleration lane with mainline
  lane drop
Ramp proper
Normal acceleration lane
Accleration lane with mainline
  lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.4
1.1
 
10.9
7.9
1.7
 
0.0
3.0
2.0
3.3
0.0
-
 
-
 
-
14
6
 
558
30
9
 
-
147
0
131
-
0
 
0
 
0
1.6
0.7
 
62.3
3.4
1.0
 
-
16.4
0.0
14.6
-
0.0
 
0.0
 
0.0
0
0
 
1
0
0
 
-
0
0
2
-
0
 
0
 
0
0.0
0.0
 
0.1
0.0
0.0
 
-
0.0
0.0
0.2
-
0.0
 
0.0
 
0.0
0
0
 
19
2
1
 
-
4
0
2
-
0
 
0
 
0
0.0
0.0
 
2.1
0.2
0.1
 
-
0.4
0.0
0.2
-
0.0
 
0.0
 
0.0
1
0
 
9
0
0
 
-
2
0
1
-
0
 
0
 
0
0.1
0.0
 
1.0
0.0
0.0
 
-
0.2
0.0
0.1
-
0.0
 
0.0
 
0.0
1
0
 
29
2
1
 
-
6
0
5
-
0
 
0
 
0
0.1
0.0
 
3.2
0.2
0.1
 
-
0.7
0.0
0.6
-
0.0
 
0.0
 
0.0
Total 33.3 895 100.0 3 0.3 28 3.1 13 1.5 44 4.9

Conversion: 1 mi = 1.61 km

Table 63. Accident Type Distribution by Ramp Segment Type for
Urban C/D Roads(1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Parked vehicle Pedestrian Bicycle Fixed object Other collision Total
Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%) Fq. (%)
Normal deceleration lane
Deceleration lane with mainline lane drop
Ramp proper
Normal acceleration lane
Accleration lane with
 mainline lane addition
Mainline weaving area
Diverge area on ramp
Merge area on ramp
Weaving area on ramp
Two-way roadway on ramp
Cross-road ramp terminal
  (stop condition)
Cross-road ramp terminal
  (free-flow)
Frontage road connection
3.4
 
1.1
 
10.9
7.9
 
1.7
 
0.0
3.0
2.0
3.3
0.0
 
-
 
 
-
 
 
-
14
 
6
 
558
30
 
9
 
-
147
0
131
-
 
0
 
 
0
 
 
0
1.6
 
0.7
 
62.3
3.4
 
1.0
 
-
16.4
0.0
14.6
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
0
0
 
0
 
-
1
0
0
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.0
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
 
 
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
 
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
 
 
0.0
7
 
2
 
61
5
 
0
 
-
19
0
35
-
 
0
 
 
0
 
 
0
0.8
 
0.2
 
6.8
0.6
 
0.0
 
-
2.1
0.0
3.9
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
3
0
 
0
 
-
1
0
1
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
0.3
0.0
 
0.0
 
-
0.1
0.0
0.1
-
 
0.0
 
 
0.0
 
 
0.0
7
 
2
 
64
5
 
0
 
-
21
0
36
-
 
0
 
 
0
 
 
0
0.8
 
0.2
 
7.2
0.6
 
0.0
 
-
2.3
0.0
4.0
-
 
0.0
 
 
0.0
 
 
0.0
Total 33.3 895 100.0 1 0.1 0 0.0 0 0.0 129 14.4 5 0.6 135 15.1

Conversion: 1 mi = 1.61 km

Table 63. Accident Type Distribution by Ramp Segment Type for
Urban C/D Roads (1993 Through 1995)(Continued)

Ramp segment type Total
length
(mi)
Total accidents Number and percentage of accidents by severity level
Head-on Sideswipe Rear-end Angle Left turn Right turn Other collision Total
F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%) F (%)
Normal deceleration
  lane
Deceleration lane
  with mainline lane
  drop
Ramp proper
Normal acceleration
  lane
Accleration lane with
  mainline lane
  addition
Mainline weaving
  area
Diverge area on ramp
Merge area on ramp
Weaving area on
  ramp
Two-way roadway
  on ramp
Cross-road ramp
  terminal
  (stop condition)
Cross-road ramp
  terminal
  (free-flow)
Frontage road
  connection
3.4
 
1.1
 
 
10.9
7.9
 
1.7
 
 
0.0
 
3.0
2.0
3.3
 
0.0
 
-
 
 
-
 
 
-
14
 
6
 
 
558
30
 
9
 
 
-
 
147
0
131
 
-
 
0
 
 
0
 
 
0
1.6
 
0.7
 
 
62.3
3.4
 
1.0
 
 
-
 
16.4
0.0
14.6
 
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
 
1
0
 
0
 
 
-
 
0
0
0
 
-
 
0
 
 
0
 
 
-
0.0
 
0.0
 
 
0.1
0.0
 
0.0
 
 
-
 
0.0
0.0
0.0
 
-
 
0.0
 
 
0.0
 
 
0.0
4
 
0
 
 
1
0
 
0
 
 
-
 
1
0
0
 
-
 
0
 
 
0
 
 
0
0.4
 
0.0
 
 
0.1
0.0
 
0.0
 
 
-
 
0.1
0.0
0.0
 
-
 
0.0
 
 
0.0
 
 
0.0
2
 
3
 
 
381
17
 
5
 
 
-
 
89
0
62
 
-
 
0
 
 
0
 
 
0
0.2
 
0.3
 
 
42.6
1.9
 
0.6
 
 
-
 
9.9
0.0
6.9
 
-
 
0.0
 
 
0.0
 
 
0.0
0
 
1
 
 
77
6
 
3
 
 
-
 
30
0
28
 
-
 
0
 
 
0
 
 
0
0.0
 
0.1
 
 
8.6
0.7
 
0.3
 
 


3.4
0.0
3.1
 
-
 
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
 
 
-
 
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
 
 
0.0
0.0
 
0.0
 
 
-
 
0.0
0.0
0.0
 
-
 
0.0
 
 
0.0
 
 
0.0
0
 
0
 
 
5
0
 
0
 
 
-
 
0
0
0
 
-
 
0
 
 
0
 
 
0
0.0
 
0.0
 
 
0.6
0.0
 
0.0
 
 
-
 
0.0
0.0
0.0
 
-
 
0.0
 
 
0.0
 
 
0.0
6
 
4
 
 
465
23
 
8
 
 
-
 
120
0
90
 
-
 
0
 
 
0
 
 
0
0.7
 
0.4
 
 
52.0
2.6
 
0.9
 
 
-
 
13.4
0.0
10.1
 
-
 
0.0
 
 
0.0
 
 
0.0
Total 33.3 895 100.0 1 0.1 2 0.2 561 62.7 147 16.4 0 0.0 0 0.0 5 0.6 716 80.0

Conversion: 1 mi = 1.61 km

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