Asphalt Review - Feb/March 2013 - Australian Asphalt Pavement ...

ASPHALT REVIEW
This control achieves the primary objective of hazard elimination,
where reasonably practicable to do so, as required under the OHS
Regulation 5.1.7.
b. Isolation of Hazard – Temporary Safety Barriers
Isolation of traffic from the work zone through the use of temporary
safety barriers has also proven to be an effective control, particularly
for longer term works adjacent to high volume traffic. They are usually
deployed where the works will be more than two weeks duration in
Victoria.
Speed limits are reduced to a maximum of 80 km/h past barriers
in Victoria, to reduce impact energy and provide an allowance for
heavier vehicle impacts when workers are present on site. On freeway
works alone since 2006, more than 500 million vehicles have passed
temporary barrier protected worksites in Victoria without penetration
or other serious incident when deployed parallel to the road.
Concrete barriers are the most common for the high speed-high
volume roads such as freeways, although steel barriers are increasing
in popularity. Performance of free standing concrete barriers in terms
of deflection under impact is superior to free standing steel barriers
However, anchoring the steel barriers improves their performance.
The speed limits may also be reduced to 60 km/h instead of 80 km/h
in these situations to further reduce heavy vehicle impact severity.
Barrier screens have proven very effective as both debris and anti-
‘gawk’ screens.
Permanent barriers are being installed because statistics show that a
significant number of vehicles are running off the road and crashing in
these areas.
Lane closures and speed reductions are unreliable controls on their
own because drivers do not always slow down and micro sleeping
drivers may pass through the worksite at any time.
c. Isolation of Hazard – (Short Term Works) Truck Mounted
Attenuator (TMA)
Where road closure (level 1 control) or safety barriers (level 2 control)
are not reasonably practicable Truck Mounted Attenuators (TMAs)
(level 3 control) are proving an effective physical isolation particularly
for short-to-medium term works. Their effectiveness continues to be
demonstrated even when they are impacted by heavy vehicles.
Many, but not all of the worksites, may also be protected by lane
closures, signs and speed reductions. Bollards may also be used but
these will not protect against a vehicle which is not under effective
control of its driver. Fatigued drivers, drugs/alcohol and distractions
such as electronic devices are some of the possible causes for drivers
losing control.
TMAs are now applied on all classes of roads in Victoria and are
mandatory on urban freeways and for line marking operations on all
roads. They are required to be TL-3 rated (100 km/h, 2 tonne vehicle
impact tested and approved), with a minimum weight of 10.4 tonne
GVM. Fifteen tonne GVM TMAs are gaining popularity for high speed
road applications and particularly freeways and interstate highways
where heavy trucks will be encountered.
For low speed roads (< 60 km/h) the use of works vehicles to “shadow”
and provide some degree of physical protection for pedestrian workers
against errant vehicles entering the worksite is always a good practice.
Such vehicles need to be heavier than two tonnes, such as small trucks;
otherwise they may be shunted significant distances.
d. Isolation of Hazard – Clearance to Traffic
Where it is not reasonably practical to eliminate the traffic hazard by
closing roads or placing physical barriers between the actual work
zone and traffic, various combinations of controls or conventional
traffic management are available to be deployed and may include a
clearance or lateral vehicle recovery/buffer zone between traffic and
the workplace.
Note that the Worksite Safety –Traffic Management Code of Practice
(2010 version) requires that the reason why the higher level controls
are not considered practical be documented taking into account
the WorkSafe Test of Reasonably Practicable. This reason needs
to be credible because clearance to traffic controls do not provide
any physical protection and are a lower level control - unless the
combination of controls includes a TMA or similar protection.
e. Combination of Controls
A combination of controls is usually deployed at roadwork sites.
Controls which eliminate hazards through road closures or isolate
through physical protection should be present to comply with the OHS
Act concept of Ensuring Health and Safety via elimination of the hazard,
or reducing the risk through applying the hierarchy of safety controls.
Typically signage and speed reductions are deployed on short term
works, although these controls are behavioural controls and not as
reliable as the higher level controls (level 1 to 3 above).
Behavioural controls require effective reinforcement and or
enforcement to be effective and the police, VicRoads Transport
Safety Services and Department of Justice Officers provide much
support in this area, providing the traffic management scheme is
correctly deployed.
Combining highly visible electronic Variable Speed Limit Signage
(VSLS) with signs warning that speed limits are enforced together with
visible patrol cars and camera presence is as demonstrated on the
longer term major worksites such as the M80 Upgrade Project.
The technology exists now for this to be potentially extended to
smaller shorter term worksites. In the United Kingdom, point-to-point
speed cameras are in place on all long term roadwork workplaces.
Speed Display Trailers, VMS Displays and Temporary Speed Humps
are also available as part of the combination of controls approach.
The safety challenge presented by the movement
of powered mobile plant and vehicles within site
The construction industry which includes road construction is
experiencing a significant number of fatalities and serious injuries
from work involving the movement of powered mobile plant and
other vehicles within sites. It is evident that the traditional controls of
reversing/tracking alarms and flashing lights are not entirely effective.
Reversing is the major cause and, although dump trucks are mainly
involved, they are by no means the only source of serious injury.
During 2011, there were five identified road construction plant
reverse-over type fatalities in Australia over a 12 month period: two in
Queensland, one in New South Wales, one in Victoria (road sweeper)
and more recently one in Canberra (grader). Because of the number
of fatalities this is our industry’s major high risk area and presents the
challenge to our industry to seek more effective and reliable controls to
prevent such incidents.
Construction plant and vehicle blind spots
It should be recognised that one of the reasons why workers and
other pedestrians are reversed over by plant and vehicles on road
construction sites is because of the large blind spots behind and
sometimes beside them.
CCTV cameras, reversing alarms and proximity warning devices are
being used to reduce the risk but reverse over fatalities still occur so we
26 ROADS FEB/MARCH 2013