Proposal to introduce requirements a) to prevent accidents when the flap covering the engine compartment is open; b) to clarify that “low-floor vehicles” concern only those vehicles that provide a single step from the ground into the low floor area and that any equipment that would counteract the intention of such single-step low-floor vehicles to facilitate access by passengers with reduced mobility is prohibited; c) to delete the prohibition on the use of laminated glass or plastic material in window panes and to delete the provision that emergency windows shall be capable of being operated from outside; d) to clarify the transitional provisions.