Setting the Debate in Context: The Key Statistical Facts ... passenger (22.7 in Sydney and 33.42% in NSW), train (10.1 % in Sydney and ... 3 K â Killed, I â Injured.
School Bus Safety
David A. Hensher
HOW SAFE ARE BUSES CARRYING SCHOOL CHILDREN? SUPPORTING EVIDENCE David A. Hensher Professor of Management and Director, Institute of Transport Studies The University of Sydney 4 February 2002 (update of November 1994 report) A contribution to the Quality Partnership between ITS and BCA (NSW)
1. Background The Bus and Coach Association (NSW) has asked for supporting evidence and commentary on a number of critical statistics which can assist in making the case that bus passenger transport in NSW is, in a relative sense, the safest form of land-based transport from the full set of available modes: automobile (driver and passenger), train, walking, motor bike, bicycle and bus (school and scheduled route). The original report, prepared in November 1994 has been updated herein to February 2002. The issue addressed in this report is the relative safety for all travellers, and in particular school children, of bus travel (currently without a seatbelt) compared to the major alternative forms of land passenger transport, especially for the journey to and from school which are primarily walking, bicycle and car passenger (with a seatbelt). 2. Setting the Debate in Context: The Key Statistical Facts A debate on safety on various transport modes must begin with identification of the amount of use of each form of transport (measured by passenger kilometres for unlinked trips), since this defines the level of exposure to risk of injury to users of each means of transport. Then when we document the actual amount of injury (by level of severity), we are able to make a very clear statement of the relative safety of alternative forms of land-based transport. The key (available) exposure data is summarised in Table 1. Table 1. A profile of modal exposure (000's of passenger kilometres per day) (a) Sydney 2000 Mode Vehicle driver Vehicle passenger Train Bus Ferry Taxi Walking Other TOTAL
Unlinked trips 7,619,762 3,573,322 784,281 960,897 37,030 99,490 5,163,525 133,742 18,372,049
Time (minutes) 142,582,457 59,439,904 22,745,893 19,824,220 956,461 1,963,160 44,114,861 4,496,711 296,123,667
Avg trip Distance time (kms) 18.71 80,258,542 16.63 32,716,221 29.00 14,505,298 20.63 6,457,063 25.83 406,708 19.73 649,775 8.54 7,888,044 33.62 668,976 16.12 143,550,627
Avg distance 10.53 9.16 18.50 6.72 10.98 6.53 1.53 5.00 7.81
Pkm 80,258,542 32,716,221 14,505,298 6,457,063 406,708 649,775 7,888,044 668,976 143,550,627
pkm% 55.91 22.79 10.10 4.50 0.28 0.45 5.50 0.47 100.00
Page 1
School Bus Safety
David A. Hensher
(b) All of NSW, 1998 Mode Bus Walk Bicycle Train Tram Taxi Ferry M/Bike Car driver Car passenger Truck Semi-trailer Other Total
Males % 4.59 1.42 0.97 2.18 0.00 0.14 0.06 1.36 62.57 20.11 2.69 0.00 3.91 100.00
Females % 5.19 1.45 0.59 0.89 0.00 0.24 0.00 0.00 38.98 52.73 0.00 0.00 0.08 100.00
Total % 4.83 1.43 0.81 1.64 0.00 0.18 0.03 0.81 52.92 33.42 1.59 0.00 2.34 100.00
Source Transport Data Centre for Sydney and Estimates for rest of NSW
Comment: Less than 5% of total exposure as defined by passenger kilometres is associated with bus travel in NSW as a whole (and in Sydney). This compares with the other key modes of car passenger (22.7 in Sydney and 33.42% in NSW), train (10.1 % in Sydney and 1.64% in NSW overall), walk (5.49% in Sydney and 1.43% in NSW), and bicycle (0.46% in Sydney and 0.81% in NSW). Table 2 summaries the degree of accident and degree of casualty associated with each mode in NSW in 2000. 1.5% of all accidents involved a bus and another mode or alone. 1.97% of all casualties (killed or injured) were involved with a bus accident. The differences in the years of data in Tables 1 and 2 is not deemed a problem for the purpose of the current assessment.
Page 2
School Bus Safety
David A. Hensher
Table 2. Accidents, casualties, type of accident, degree of accident, degree of casualty by mode, NSW, 2000 Degree of Accident
2
3
Type of 1 Accident Car Accident Light Truck Accident Heavy Truck Accident Heavy Rigid Truck Accident Articulated Truck Accident Bus Accident Emergency Vehicle Accident Motorcycle Accident Pedal Cycle Accident Pedestrian Accident
421 93 104 37 69 13 1 62 6 113
(1%) (1%) (3%) (2%) (4%) (2%) (0%) (3%) (0%) (4%)
18,918 2,723 1,213 598 643 387 152 1,966 1,227 2,871
(39%) (39%) (40%) (39%) (41%) (48%) (46%) (87%) (99%) (96%)
N 29,119 4,176 1,720 906 842 398 176 233 3 3
(60%) (60%) (57%) (59%) (54%) (50%) (53%) (10%) (0%) (0%)
Total Accidents 48,458 (100%) 6,992 (100%) 3,037 (100%) 1,541 (100%) 1,554 (100%) 798 (100%) 329 (100%) 2,261 (100%) 1,236 (100%) 2,987 (100%)
All Types of Accidents
543
(1%)
21,863
(40%)
30,508
(58%)
52,914
F
IA
(100%)
Degree of Casualty Total Killed K I & Injured 478 25,442 25,920 97 3,717 3,814 122 1,611 1,733 40 792 832 84 870 954 13 569 582 1 231 232 64 2,192 2,256 6 1,261 1,267 114 3,076 3,190 603
28,812
29,415
Note: Percentages of all accidents involving those traffic type units are shown in brackets. 1 Accident categories listed are those involving at least one traffic unit of that type. 2 F – Fatal Accident, IA – Injury Accident, N – Non-Casualty Accident 3 K – Killed, I – Injured IMPORTANT: The ‘Type of Accident’ categories in this table are not mutually exclusive and must therefore not be added together. For example, an accident involving both a car and a motorcycle will be included in both ‘Car Accident’ and ‘Motorcycle Accident’ categories. Source: Roads and Traffic Authority of NSW (2001) Road Traffic Accidents in NSW –2000 Road Safety Bureau, Sydney, June.
Page 3
School Bus Safety
David A. Hensher
One has to be extremely careful in interpreting the statistics in Table 2, since all casualties associated with a particular mode involved in an accident cannot be assumed to be travelling in that mode. An accident between a bus and a car, for example, as reported in the statistics is unable to identify whether the injured were travelling in the bus or in the car. Nevertheless even under the less favourable assumption for buses, less than 2% of all casualties are associated with an accident in which a bus is involved. The data above is not appropriate for studying the risk profile of each mode for school children. To map exposure with casualty to establish risk for the population as a whole and for school children, we need to seek out other data. We have been able to put together some statistics from the NSW Transport Data Centre’s Household Travel Survey for Sydney (purchased by ITS), extrapolated to all of NSW based on the earlier 1995 data. The TDC data (Table 3) needs some revision in order to map it back to the modes of interest. Table 4 summarises the data required to derive the risk factors for each mode. Table 3 1999 HTS data - average weekday - GMR - Kms travelled by Mode for Unlinked trips
Mode Vehicle driver (including m/cycles) Vehicle passenger (including m/cycles) Train Walking (including pram) Bus Taxi Bicycle Ferry Other Total
Total trips Total kms Percent 98,544,579 57.3 38,186,707 22.2 16,016,281 9.3 9,199,325 5.3 7,972,360 4.6 767,760 0.4 537,713 0.3 437,971 0.3 304,113 0.2 171,966,810 100.0
Trips made by 5-16 yr olds Total kms Percents 40,497 0.2 11,737,683 61.7 3,206,271 16.9 2,204,905 11.6 1,369,912 7.2 242,506 1.3 112,631 0.6 50,013 0.3 48,024 0.3 19,012,443 100.0
Table 4. Casualties by mode and age. Figures subject to rounding error. RRFI = relative risk factor index. (*) = not able to separate so treat as one mode. We exclude trucks Mode
Bus/coach Car driver Car passenger (incl taxi)
Train and ferry M/cycle rider M/cycle passenger Bicycle Pedestrian Total
Casualties: 5-16 year old (%) (1) 3.83 2.49 46.46 0.18 1.89 0.83 17.66 26.66 100.00
Total pkm's 5-16 yrs (%) (2) 7.20 0.20 63.09 17.20 0.15 0.16 0.60 11.40 100.00
Casualties: Total (%) all ages (3) 1.97 42.82 25.20 5.15 7.14 0.63 5.38 11.71 100.00
Total pkm's (%)
RRFI all ages
RRFI 5-16 yrs
(4) 4.60 56.89 22.50 9.60 0.51 0.30 0.30 5.30 100.00
(=3/4) 0.43 0.75 1.12 0.54 14.01 2.09 17.93 2.21 -
(=1/2) 0.53 12.46 0.74 0.01 12.58 5.17 29.43 2.34 -
Source: Transport Data Centre, February 2002. The advice of Tim Raimond is very much appreciated. A casualty is an accident in which at least one person was injured or killed.
Page 4
School Bus Safety
David A. Hensher
The last two columns of Table 4 are the most useful. They indicate the contemporary record of all casualties relative to the exposure to the transport system as measured by passenger kilometres (from unlinked trips). The higher the index, the greater the risk. As you can see, for road-based transport, motor cycle riders have the highest risk factor, and bus passengers the lowest risk factor. Car drivers and passenger have a higher risk factor than bus. For all passengers: bus passengers contribute 4.6% of total passenger kilometres yet only 1.97% of casualties; in contrast pedestrians contribute only 5.3% of passenger kilometres yet are the source of 11.71% of casualties. Motorcycle riders undertake 0.51% of passenger kilometres yet contribute 7.14% to casualties. However, for the carriage of school children, buses are overwhelmingly safer than any other road mode (including walking which is usually along the side of a road). Train is the only safer mode. For school children: bus passengers contribute 7.2% of all passenger kilometres yet only 3.83% of all school children casualties; in contrast car passengers contribute 63.09% of pkm's but 46.46% of school children casualties. For bicycle riders they contribute .6% of pkm's but 17.66% of school children casualties. Comment: bus travel is overall, the safest form of land passenger transport for all passengers and the safest for school children between 5 and 16 years old if we exclude train (Table 5). It is 23 times safer than driving, 1.38 times safer that being driven in a car, 23 times safer than driving a motorbike, 55 time safer than using a bicycle and 4.4 times safer than walking. Table 5. Relative Risk of Children Aged 5-16 years old travelling by bus Mode Bus/coach Car driver Car passenger (include taxi) Train and ferry M/cycle rider M/cycle passenger Bicycle Pedestrian
Relative Risk of Bus 1.00 23.41 1.38 0.02 23.62 9.71 55.27 4.39
Page 5
School Bus Safety
David A. Hensher
Relative Risk Of Bus Travel for School Aged Children 60
50
40
30
20
10
0 Bus/coach
Car driver
Car passenger (include taxi)
other (include train and ferry)
M/cycle rider
M/cycle passenger
Bicycle
Pedestrian
Mode of Transport
3. References Roads and Traffic Authority of NSW (2001) Road Traffic Accidents in NSW –2000 Road Safety Bureau, Sydney, June.
Page 6
