In a comment published in the International Forum for Road Transport Technology’s latest Newsletter, Scania’s Erik Dahlberg welcomed the European Commission’s most recent attempt to re-open the debate on a revision of Directive 96/53, but said it should retain a certain degree of flexibility as demonstrated in the Performance Based Standards (PBS) approach.
“At first sight, the proposal appears to be very promising since it intends to introduce a form of PBS, giving manufacturers and hauliers a degree of freedom in designing and operating more efficient vehicle combinations,” he said.
“The proposal, if properly implemented, will be a clear improvement in the existing legislation by allowing more flexibility in the design for improved aerodynamics. However, the purpose of aerodynamic improvements may be lost if the new, unclear demands for increased safety, a regulatory area for which standards already exist in the Type Approval Directives, are implemented.”
According to Dahlberg, flexibility may also be reduced if the proposed new certification for aerodynamic improvement is introduced. “In real life, there is no clear relation between a more aerodynamic cab and a more aerodynamic vehicle; the complete vehicle, including body, trailer and its operation, must be understood. In addition, the proposal requires a relative rather than absolute comparison for these requirements, which complicates the procedure further.”
Dahlberg said any type approval requirement should to be stated in absolute terms in order to be legally secured. “Once adopted, [the Directive] adds far-reaching possibilities for the European Commission to make derogations on the technical demands without political approval, i.e. no formal legislative procedure for timeline and stakeholder consultation for changes to the PBS in the future.”
Responding to Dahlberg’s comment, Australian PBS expert Rob Di Christoforo said that one could mount arguments for the opposite as well. “With the EU approach, once the laborious task of amending a regulation is complete, it has immediate and widespread impact with little burden on the industry. With the PBS approach, on the other hand, benefits accrue to only the small portion of the industry that spends the time and money to pursue applications, and conditions of operation can be very strict and cumbersome.”
He argued that PBS vehicle configurations that are already very popular in countries like Australia and are close to becoming common should be brought back into normal regulations.
A possible length extension of up to two meters for the vehicle combination is in discussion, divided between the front and rear end. The additional length may only be used for aerodynamic and safety purposes; no increase in the load capacity will be permitted. Vehicle manufacturers have calculated potential fuel savings of between one and three per cent by extending the cab front, making the vehicle more optimised with respect to airflow. The corresponding saving at the rear, by introducing flaps at the trailer end, constituting a so-called boat tail, is five to six per cent.