Truck or heavy vehicle crashes feature regularly in print, online and television media. When a heavy vehicle is involved in a serious crash, particularly one involving loss of human life, this often triggers public debate about the road conditions at the location of the crash, the factors that may have contributed to the crash and how the government is addressing the issue. Recently, there have been a number of high profile stories involving speeding heavy vehicles (eg Cuneo 2012; Waters 2012) that have led to renewed public debate focused on the types of interventions necessary to effectively respond to truck drivers who regularly speed and heavy vehicle companies that tamper with heavy vehicle speed limiter equipment or encourage other practices that flout the law.
Effective responses to a problem, which derive long-term benefits, require a solid understanding of that problem. However, there is surprisingly little publicly available research about the nature of offending behaviour that is committed by heavy vehicle drivers and operators, particularly heavy vehicle speeding. This paper goes some way towards redressing this gap by describing the types of heavy vehicles that are most often detected speeding and the typical circumstances in which this occurs. It then discusses the implications of these findings for Australian policy and practice at national, and state and territory levels.
What is heavy vehicle speeding?
Speeding most commonly refers to an offence where a vehicle travels faster than the signposted speed limit designated for a given area. However, it can also be defined as driving at a speed that is inappropriate for the conditions (RTA 2003). Heavy vehicles (vehicles whose Gross Vehicle Mass is in excess of 4.5 tonnes) are also subject to speed restrictions that do not apply to other vehicles. For instance, the maximum speed limit for heavy trucks and road trains (7+ axle vehicles with either 2 or 3 trailers) in New South Wales is 100 km/h and 90km/h respectively and differential speed limits may apply to heavy vehicles in certain locations, such as on steep inclines (RTA 2003).
What is already known about heavy vehicle speeding?
Although very little research has been published on the prevalence of heavy vehicle speeding on Australian roads, available evidence suggests that it is common. One way heavy vehicle speed information is obtained is through weigh-inmotion stations. Weigh-in-motion stations collect information about traffic volume and loading, which are important in determining (among other things) appropriate road treatments, the value of freight traveling on the roadway system and the relative cost responsibility of different road users. Weigh-in-motion data from a number of Australian states (excluding Western Australia and the Northern Territory) found that 1 7 percent of two-axle trucks and 26 percent of six-axle articulated trucks exceeded the speed limit, although the majority of trucks (81 % of 2-axle trucks and 87% of 6-axle trucks) were detected speeding at no more than 1 0km/h over the posted limit (George 2003). Further, qualitative research based on interviews with heavy vehicle drivers suggests that up to 55 percent of truck drivers had received at least one speeding fine while driving a heavy vehicle within the 1 2 months prior to interview (AMR Interactive 2006; Hensher et al. 1991).
However, an analysis of speed data from weigh-in-motion sites in New South Wales and Victoria between 1996 and 2002 indicates that only a minority of heavy vehicle drivers exceed the speed limit by 10km/h or more (NTC 2005), which is consistent with the findings for other motorists based on speed data obtained from Global Positioning System technology (Ellison & Greaves 2010). Moreover, heavy vehicle drivers have been found to be less ikely to speed overall than other classes of driver, as measured by traffic surveys conducted at fixed speed cameras sites (Friswell, Irvine & Williamson 2003). …