16a Look right by railway truck ((5) - Lorry - 'lo' (look) + r(ight) + r(ailwa)y
13d "Cow being not as fast, doesn't start (5) - (S)Lower - low = moo
Hi TPH - it's always nice to include the full clues, numbers of letters & any you've placed, so that people without the puzzle can more readily help you - thanks! :-)