That’s the verdict of the latest Policy Brief published by the International Transport Forum at the OECD.

The latest Policy Brief follows on from previous International Transport Forum work undertaken in 1999 that highlighted the high cost of addressing environmental goals through such schemes. It revisits the claims that such incentives, as well as kick-starting consumer spending and assisting car manufacturers and dealers, can offer substantial environmental and safety benefits.

The ITF study looks at three schemes: the French Prime à la casse, the German Umweltprämie and the US CARS programme. Results are based on a detailed investigation of 2.8 million individual transactions simplified into three car classes, which serve as the basis for the emissions and safety analysis.

The study says that there are two important points to be noted. Firstly, that as vehicles get older, they are generally driven less. Conversely, new vehicles tend to be driven more than older vehicles. Thus, while new vehicles may emit less than the older vehicles they replaced and may have more advanced safety features, the fact that they are driven more somewhat erodes these gains.

Secondly the study adds that vehicle scrapping schemes generally serve only to advance purchase decisions that would have otherwise taken place at a later date. The main impacts of fleet renewal schemes stem from early fleet replacement compared to the “business-as-usual” case. The end-of-fleet replacement schemes are often accompanied by a drop-off in car sales.

It also says that the gains made from the schemes were insufficient to make up for the value of the scrapped cars – in some cases the net losses were large. And the study adds that the claims of reduced environmental impacts and improved safety should not serve as the main argument for scrapping programmes.

The ITF Policy Brief can be found on its website at http://www.internationaltransportforum.org