Lorry to the Glue Factory

Been thinking recently about the books I read in school - specifically animal farm - you must remember the big stupid horse named Boxer? he was sent to the glue factory to be made into glue, because he was old and stupid. Its a sad story but it has strong ideals and thoughts behind it. Should they do the same to lorries - should lorries be broken down for salvage? or should they be allowed to continue to drive round? I am so sure older lorries really negatively affect our pollution output as a country. Down with the older polluting cars - up with the newer turbo diesel models!!! thats what I say - random outburst over ;P