Actually, that "researcher" and a good many others like him/her (along with quite a few more elected officials than one might believe likely) do know very well what efforts the railroad and trucking industries and their suppliers have made in reducing emissions and improving fuel economy. The reason why they don't show that knowledge is because it wouldn't fit well with whatever their goals or agendas may be (none of which are obviously very railroad or truck-friendly). It's far easier for them to ignore the truth than it is for them to work their agendas around it (and much easier than trying to incorporate that truth into an agenda which contradicts it), after all...