Table 1 Descriptive statistics of potential crash predictors for segments and intersections

Variables [for segments]

Modalities

Mean (st. dev.)/ Counts

Min-max/ Percentages

Mean (st. dev.)/ Counts

Min-max/ Percentages

Mean (st. dev.)/ Counts

Min-max/ Percentages

Fatal+Injury (F + I) crashes

Numerical

689

–

283

–

406

–

F + I crashes/segment/year

Numerical

0.43 (0.86)

0–6

0.30 (0.68)

0–5

0.63 (1.03)

0–6

One-way

0 – No (two-way)

0–130

0–0.41

0–0

0–0.00

0–130

0–1.00

1 – Yes

1–190

1–0.59

1–190

1–1.00

1–0

1–0.00

One-lane

0 –No (multilane)

0–226

0–0.71

0–96

0–0.51

0–130

0–1.00

1 – Yes

1–94

1–0.29

1–94

1–0.49

1–0

1–0.00

AADT

Numerical

8637.2 (5889.3)

300.0–29,960.0

6228.8 (4569.5)

300.0–22,600.0

12,157.1 (5843.5)

1160.0–29,960.0

Length (m)

Numerical

138.3 (183.3)

30.0–1510.0

124.1 (175.4)

30.0–1510.0

159.1 (193.0)

30.0–1415.0

Speed Limit = 50 km/h

0 – Yes

0–309

0–0.97

0–190

0–1.00

0–119

0–0.92

1 – No (>  50 km/h)

1–11

1–0.03

1–0

1–0.00

1–11

1–0.08

Road width (m)

Numerical

10.5 (3.0)

4.1–28.0

9.9 (2.6)

5.5–20.0

11.3 (3.5)

4.1–28.0

Type of lanes

0–1 lane

0–116

0–0.36

0–116

0–0.61

0–0

0–0.00

1 – >  1 lane (up to 3)

1–74

1–0.23

1–74

1–0.39

1–0

1–0.00

2–1 + 1 lane

2–89

2–0.28

2–0

2–0.00

2–89

2–0.68

3 – >  1 + 1 lanes (up to 3 + 3)

3–41

3–0.13

3–0

3–0.00

3–41

3–0.32

Density of minor roads/ driveways per km

Numerical

26.9 (26.0)

0.0–143.0

22.4 (22.8)

0.0–142.9

33.3 (28.9)

0.0–143.0

Vertical signs on minor roads/ driveways

0 – No

0–256

0–0.80

0–158

0–0.84

0–98

0–0.75

1 – Yes

1–64

1–0.20

1–32

1–0.16

1–32

1–0.25

Poor maintenance of pavements

0 – No

0–71

0–0.22

0–49

0–0.26

0–22

0–0.17

1 – Yes

1–249

1–0.78

1–141

1–0.74

1–108

1–0.83

Road markings

0 – No/Partially absent or illegible

0–60

0–0.19

0–24

0–0.13

0–36

0–0.28

1 – Illegible

1–124

1–0.39

1–82

1–0.43

1–42

1–0.32

2 – Yes

2–136

2–0.42

2–84

2–0.44

2–52

2–0.40

Parking type

0 – Prohibited

0–85

0–0.27

0–26

0–0.14

0–59

0–0.45

1 – One side

1–109

1–0.34

1–74

1–0.39

1–35

1–0.27

2 – Both sides

2–119

2–0.37

2–87

2–0.46

2–32

2–0.25

3 – Mixed

3–7

3–0.02

3–3

3–0.02

3–4

3–0.03

Cycle paths

0 – No

0–291

0–0.91

0–163

0–0.86

0–128

0–0.98

1 – Yes

1–29

1–0.09

1–27

1–0.14

1–2

1–0.02

Sidewalks

0 – No

0–31

0–0.10

0–4

0–0.02

0–27

0–0.21

1 – Yes

1–289

1–0.90

1–186

1–0.98

1–103

1–0.79

Median

0 – No

0–244

0–0.76

0–114

0–0.60

0–130

0–1.00

1 – Yes

1–76

1–0.24

1–76

1–0.40

1–0

1–0.00

Bus stop

0 – No

0–227

0–0.71

0–143

0–0.75

0–84

0–0.65

1 – Yes

1–93

1–0.29

1–47

1–0.25

1–46

1–0.35

Bus/taxi lane

0 – No

0–284

0–0.89

0–154

0–0.81

0–130

0–1.00

1 – Yes

1–36

1–0.11

1–36

1–0.19

1–0

1–0.00

Land use

0 – Residential

0–115

0–0.36

0–71

0–0.37

0–44

0–0.34

1 – Mainly commercial

1–150

1–0.47

1–110

1–0.58

1–40

1–0.31

2 – Other

2–55

2–0.17

2–9

2–0.05

2–46

2–0.35

Variables [for intersections]

Modalities

Mean (st. dev.)/ Counts

Min-max/ Percentages

Mean (st. dev.)/ Counts

Min-max/ Percentages

Mean (st. dev.)/

Counts

Min-max/ Percentages

Fatal+Injury (F + I) crashes

Numerical

906

–

232

–

674

–

F + I crashes/intersection/year

Numerical

1.51 (1.84)

0–15

0.97 (1.41)

0–15

1.87 (1.99)

0–12

Traffic lights

0 – No

0–59

0–0.49

0–38

0–0.79

0–21

0–0.29

1 – Yes

1–61

1–0.51

1–10

1–0.21

1–51

1–0.71

Type = 4 legs

0 – No

0–48

0–0.40

0–48

0–1.00

0–0

0–0.00

1 – Yes

1–72

1–0.60

1–0

1–0.00

1–72

1–1.00

Main AADT

Numerical

12,192.4 (5313.2)

2475.0–23,680.0

12,588.4 (5350.8)

3550.0–22,340.0

11,928.4 (5309.1)

2475.0–23,680.0

Secondary AADT

Numerical

5084.1 (4271.5)

300.0–17,880.0

4008.3 (3897.4)

300.0–18,520.0

5801.4 (4384.2)

345.0–17,880.0

Total AADT

Numerical

17,276.5 (7981.8)

4175.0–41,560.0

16,596.6 (7018.3)

5420.0–32,300.0

17,729.7 (8582.2)

4175.0–41,560.0

Main AADT/ Total AADT

Numerical

0.53 (0.03)

0.50–0.62

0.55 (0.03)

0.50–0.62

0.53 (0.02)

0.50–0.61

Lane balance

0 – No

0–81

0–0.67

0–38

0–0.79

0–43

0–0.60

1 – Yes

1–39

1–0.33

1–10

1–0.21

1–29

1–0.40

Median on the main road

0 – No

0–100

0–0.83

0–48

0–1.00

0–52

0–0.72

1 – Yes

1–20

1–0.17

1–0

1–0.00

1–20

1–0.28

Median on the secondary road

0 – No

0–107

0–0.89

0–43

0–0.90

0–64

0–0.89

1 – Yes

1–13

1–0.11

1–5

1–0.10

1–8

1–0.11

Entering lanes on the main road

Numerical

1.5 (1.1)

0.0–5.0

1.1 (1.0)

0.0–4.0

1.8 (1.1)

0.0–5.0

Mean lane width at intersections (m)

Numerical

4.5 (1.1)

2.8 (8.7)

4.3 (1.0)

2.8–6.6

4.6 (1.2)

2.8–8.7

Critical sight distance (m)

Numerical

31.2 (26.0)

0.0–139.5

30.0 (28.1)

0.0–139.5

32.0 (24.6)

1.6–100.0

One-way legs

Numerical

1.7 (1.5)

0.0–4.0

1.4 (1.1)

0.0–3.0

2.0 (1.6)

0.0–4.0

Specialized turning lane

0 – No

0–88

0–0.73

0–43

0–0.90

0–45

0–0.63

1 – Yes

1–32

1–0.27

1–5

1–0.10

1–27

1–0.37

Traffic control

0 – No

0–22

0–0.18

0–16

0–0.33

0–6

0–0.08

1 – Give-way/Stop

1–37

1–0.31

1–22

1–0.46

1–15

1–0.21

2 – Traffic lights

2–35

2–0.29

2–7

2–0.15

2–28

2–0.39

3 – Traffic lights with dedicated turning

3–26

3–0.22

3–3

3–0.06

3–23

3–0.32

Poor maintenance of pavements

0 – No

0–18

0–0.15

0–9

0–0.19

0–9

0–0.13

1 – Yes

1–102

1–0.85

1–39

1–0.81

1–63

1–0.87

Cycle path crossing

0 – No

0–103

0–0.86

0–36

0–0.75

0–67

0–0.93

1 – Yes

1–17

1–0.14

1–12

1–0.25

1–5

1–0.07

Sidewalks

0 – No

0–8

0–0.07

0–3

0–0.06

0–5

0–0.07

1 – Yes (both sides)

1–112

1–0.93

1–45

1–0.94

1–67

1–0.93

Bus stops

0 – No

0–111

0–0.93

0–46

0–0.96

0–65

0–0.90

1 – Yes

1–9

1–0.07

1–2

1–0.04

1–7

1–0.10

Bus/taxi lanes on intersecting roads

0 – No

0–92

0–0.77

0–43

0–0.90

0–49

0–0.68

1 – Yes

1–28

1–0.23

1–5

1–0.10

1–23

1–0.32