“Hauliers of aggregates and hardware material often install a ‘greedy bar’ in order to extend the truck’s capacity beyond the stipulated maximum gross weight.
“The ‘greedy bar’ is removed whenever the truck has to be inspected by the Licensing Authority.”
The following Letter to the Editor, which deals with aspects of the new Road Traffic (Amendment) Bill, was submitted to Wired868 by traffic and transportation engineer Dr Rae J Furlonge:
Road vehicle weight limits are not enforced in most Caribbean countries. That is due to several factors, such as opposition by truckers, the lack of understanding of the precise effects of overloading on the deterioration of road surfaces, lack of political will and an insufficient number of available vehicle weighing scales.
Even if legislation is enforced, the low fines plus the fact that the truckers are allowed to proceed after paying the fines will not ensure that axle load limits are observed. The net effect on the road network is premature failure of the roadway pavements and an increase in the maintenance budget. These costs are not usually borne by the road users responsible for creating the problem.
Roads are designed to accommodate a projected number of axle load repetitions of a specific magnitude for a projected service life. The damage created by traffic loads is expressed in terms of a reference axle load.
Projected axle loads from different vehicle configurations are converted into an equivalent number of 8,000-kg single axle loads. These equivalent single axle loads (ESALS) are the basis for determining the thickness of the road structure required to provide the desired design life and thus its cost.
The effect of a single axle load on a road increases by about a fourth power of axle load. For example, although a 16,000-kg single axle load is only twice as large as an 8,000-kg single axle load, it causes 17 times more loss in the life of a road.
In addition to the impacts on road service life, increasing axle loads may also increase the level of maintenance required between major resurfacings. As expected, using tandem axles rather than single axles reduces the damage to the pavement.
Very few of the Caribbean countries can give evidence of: (a) the extent of overloading, that is, how many vehicles are carrying loads beyond the maximum vehicle and axle limits, (b) the categories/classes of these vehicles and types of cargo being carried, (c) which routes and road links these vehicles are using, and (d) the degree of overloading by each category/class of vehicles, that is, the percentage of overloading of each category/class of vehicles.
Implementing an effective vehicle weight control programme is impossible in the absence of this data and so, without it, proper management of routine road maintenance becomes quite difficult.
With respect to vehicle overloading, the following are specific concerns as regards the Trinidad and Tobago Motor Vehicles and Road Traffic (Amendment) Bill, 2017:
- The changes to Section 97(2) and 98(1) constituted mere editing. Vehicle overloading also appears in the original Act in section 23, and the current amendment addresses only sub-section 23(1) (d) concerning window tint. So why such minor amendments to what is a critical matter of vehicle overloading?
- Section 97(1) of the existing Act directs the vehicle or trailer to the nearest weighbridge for the purpose of weighing its load. Which weighbridge of the Licensing Authority is operational?
The 1994 Weigh-in-Motion Study done by Lea-Trintoplan on behalf of the Ministry of Works and Transport, Government of Trinidad and Tobago showed that there was a significant amount of vehicle overloading on the nation’s roadways.
The incidence of overloading was greatest on the Churchill-Roosevelt Highway, the Uriah Butler Highway and the Eastern Main Road in Valencia. The main offenders were semi-trailers with three or four axles, closely followed by straight trucks with double wheels on the rear axle.
Hauliers of aggregates and hardware material often install a “greedy bar” in order to extend the truck’s capacity beyond the stipulated maximum gross weight. The “greedy bar” is removed whenever the truck has to be inspected by the Licensing Authority.
- In the T&T Parliament, Faris Al Rawi, the Honourable Attorney General, referred to the Jamaica example; let me refer to Jamaica a bit. Jamaica has given priority to the control and enforcement of vehicle overloading. What is the extent of their overloading?
- As was the case in T&T, the number of heavy vehicles in Jamaica doubled over the period 1994-2006.
- The typical truck is at least 65% overweight—quite a number of units are carrying twice the legal axle loads. This causes in excess of 10 times the damage done by a vehicle carrying legal axle loads and cuts in half the life of the roadway based on design loads.
Several years ago, Jamaica established a four-man Vehicle Weight Enforcement Unit at the Island Traffic Authority (ITA):
- The Unit has received hands-on training on AX900 Portable Scales.
- A Comprehensive Vehicle Weight Enforcement Manual has been developed
- Two (2) portable weigh scales have been procured
Several improvements have been proposed to the existing regulations in Jamaica:
- An increase in the sum payable as a penalty for breaches or violations of the law.
- The person in charge of the vehicle shall ensure that another vehicle is dispatched and the excess goods be off-loaded onto another vehicle in a manner not likely to cause obstruction to the traffic and the offending vehicle or trailer shall not proceed until it has satisfied the prescribed weight limit.
- “The ITA may, after seven (7) days, dispose of non-perishable goods stored [removed from overloaded vehicles] by means of sale or such other manner as it thinks fit. For perishable goods, the ITA may sell or otherwise dispose of them before the seven (7) days.” The ITA does not want to get into the storage and vending business.
- Axle configuration details to be put into regulations
- No objection to varied license fees favouring increased axles but max vehicle length of 17.3m must not be exceeded
- I have recommended that:
- permanent weight-restricted bridges be placed at the terminal gates of all ports in order to address container truck overloading;
- the Licensing Authority acquire portable weigh bridges and;
- vehicle weight regulations be enforced in a consistent and effective manner. This enforcement should be highly visible in order to serve as a deterrent, a warning and/or a reminder to others.