Risk classification system tool
Principles
Baseline
(Score=0)
Low fatigue likelihood/safety
risk
Medium fatigue
likelihood/safety risk
High fatigue
likelihood/safety risk
(Score = 1)
(Score = 2)
(Score = 3)
Work-related Rest breaks: breaks from driving within work opportunity (WO) to reduce performance impairment due to extended time-on-task
1. Reduce the time spent continuously working in the
WO
>20% of time in the WO
>15-20% time in the WO
>10-15% time in WO
6-10% time in WO*
2. The more frequent breaks from driving the better
≥ 15 mins in every 2 hrs
≥ 15 mins in every 3 hr
≥ 15 mins in every 4 hr
≥ 15 mins in every 5 hr
Recovery breaks: sleep opportunities between work opportunities (WO's) to ensure sufficient time to obtain sufficient sleep to prevent unsafe levels of fatigue
3. Ensure an adequate sleep opportunity (SO) in order
to obtain sufficient sleep
Recovery breaks ≥ 12 hrs
Recovery breaks > 9hrs
Recovery breaks >8-9hrs
Recovery breaks 7-8hrs
4. Maximise adequate night sleep
All Recovery breaks include
23:00 to 07:00 period
All Recovery breaks include
00:00 to 06:00 period
More than half of Recovery
breaks include 00:00 to 06:00
period
Less than half of Recovery
breaks include 00:00 to
06:00 period
5. Minimise shifts ending between 00:00 to 06:00h
No WO's end in 23:00 to 07:00
period
No WO's end in 00:00 to 06:00
period
Less than half of WO's end in
00:00 to 06:00 period
More than half of WO's end
in 00:00 to 06:00 period
6. Minimise extended shifts
<12 hours WO between
Recovery breaks
<13 hour WO between Recovery 13 - 14 hour WO between
breaks
Recovery breaks
> 14-17 hour WO between
Recovery breaks
Reset breaks: breaks in sequences of WO to eliminate the build-up of unsafe levels of fatigue over an extended sequence of shifts
7. Prevent accumulation of fatigue with Reset breaks
at least 30hrs and including two night periods, 00:0006:00)between work sequences
≤ 2 days (48hrs) between Reset
breaks
≤3 days (72 hrs) between Reset
breaks
≤7 days (≤168 hrs) between
Reset breaks
>7 days to 12 days (> 168 288hrs) between Reset
breaks
*This parameter is limited by the outer limit of a 17 hour work opportunity with a minimum of 1.5 hours work related rest breaks. Therefore a lower percentage of 6% for work related rest
breaks only applies to work opportunities of less than 17 hours
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201503-0152
National Heavy Vehicle Regulator
Risk classification system tool
Risk Assessment Sheet
Baseline
Risk Category
Medium
Low
High
Exceeds Limit
Work Opportunity Length
(hours)
Principle 1 – Reduce time spent continuously working in the Work Opportunity
1. Determine the number of work hours. (Rows from 8 to 17 hours)
2. Determine the number of within rest minutes. (Columns from 60 mins to 150 mins)
3. The percentage in the cell where the number of work hours and work rest minutes cross is your raw
score.
8
9
10
11
12
13
14
15
16
17
60
12.50%
11.11%
10.00%
9.09%
8.33%
7.69%
7.14%
6.67%
6.25%
5.88%
75
15.63%
13.89%
12.50%
11.36%
10.42%
9.62%
8.93%
8.33%
7.81%
7.35%
Within Work Rest (mins)
90
105
120
18.75%
21.88%
25.00%
16.67%
19.44%
22.22%
15.00%
17.50%
20.00%
13.64%
15.91%
18.18%
12.50%
14.58%
16.67%
11.54%
13.46%
15.38%
10.71%
12.50%
14.29%
10.00%
11.67%
13.33%
9.38%
10.94%
12.50%
8.82%
10.29%
11.76%
135
28.13%
25.00%
22.50%
20.45%
18.75%
17.31%
16.07%
15.00%
14.06%
13.24%
150
31.25%
27.78%
25.00%
22.73%
20.83%
19.23%
17.86%
16.67%
15.63%
14.71%
Principle 2 – The more frequent breaks from driving the better
1. Determine the longest period of continuous driving.
Maximum time continuous driving (Hours)
>2 to 3
>3 to 4
>4 to 5
0 to 2
6
Principle 3 – Ensure an adequate sleep opportunity (SO) in order to obtain sufficient sleep
1. Determine the length of the shortest sleep opportunity.
13
12
11
Sleep Opportunity (SO) - (Hrs)
10
9
8
7
6
Principle 4 – Maximise adequate night sleep
2. Determine the number of sleep opportunities
3. Determine the number of sleep opportunities including the period between midnight and 6am.
4. Calculate the percentage of sleep opportunities including midnight and 6am to sleep opportunities.
5. The percentage is the raw score and should fall into a risk category below.
23:00 - 07:00
100%
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Minimise night shifts (Hrs)
0:00 - 06:00
0:00 - 06:00
100%
99% - 51%
201503-0152
0:00 - 06:00
50% - 1%
National Heavy Vehicle Regulator
Risk classification system tool
Principle 5 – Minimise shifts ending between 00:00 to 06:00
6. Determine the number of sleep opportunities
7. Determine the number of work opportunities ending between midnight and 6am.
8. Calculate the percentage of work opportunities ending between midnight and 6am to sleep
opportunities.
9. The percentage is the raw score and should fall into a risk category below.
Minimise night shifts (Hrs)
0:00 - 06:00
0:00 - 06:00
0%
1% - 49%
23:00 - 07:00
0%
0:00 - 06:00
50% - 100%
Principle 6 – Minimise extended shifts
10. Determine the number of hours between sleep opportunities/Reset rest breaks.
10
11
Minimise extended shifts (Hours)
13
14
15
12
16
17
18
Principle 7 – Prevent accumulation of fatigue with Reset rest breaks
11. Determine the number of days between Reset rest breaks.
(Reset rest breaks are rest breaks of at least 30 continuous hours in duration that span two consecutive midnight to 6am periods.)
1
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2
3
4
5
Reset Rest Breaks (days)
6
7
8
9
201503-0152
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11
12
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National Heavy Vehicle Regulator