In London, overall crowding across both peaks in 2012 was lower than in 2011. However, over 100,000 passengers had to stand at trains' busiest points in the morning peak, a fifth of the overall total.
More top news
The twins cubs, which were born in June, have been named Bert and Ernie after characters from Sesame Street.
The two victims died from their injuries in hospital after the explosion in Hertfordshire.
Investigations are continuing into the cause of the crash in chigwell which killed both people on board.