(This is the text I put in the BR feedback form. In hindsight, it is probably a bit aggressive.)

Guys,

The usability of your train times service is, frankly, pretty shocking. :-| 

Here are some deficiencies I see in the current interface; see the bottom of
this message for an alternative UI suggestion.

- You cunningly set the default time to "now", but don't set a default date. If
  I just change the time to "1pm", and it's now 10am, which day do you think I
  mean? If I don't specify a date, it should assume I mean "today" if the time
  if after "now", or tomorrow, if it's before "now". 

- Better yet, it should have the quick-access radio buttons the previous
  incarnation had for "today" and "tomorrow". Even better, the date field should
  use some available module like Perl's Date::Parse, so it can understand 
  natural language dates like "12th April".

- If I want to go from Gordon Hill to Kings Cross, it asks me if I mean Kings
  Cross Thameslink or London Kings Cross. Well, duh. :-) There's a direct train
  to one, and not to the other, and they are right next door. Even if I ask for
  "direct trains only" it still asks me, even though there are no direct trains
  from Gordon Hill to Kings Cross Thameslink.

- The text boxes for entering station names are too small. size="9"? How many
  stations are nine letters or less?

- Depart/Arrive should be a radio button - it's a choice of two things, not an
  arbitrary-length list. 

- The time entry should be freeform text, and again allow things like "12pm",
  1:34 (where it would sensibly assume 1.34pm and not 1.34 in the morning) and
  so on. Ambiguities could be clarified later, but it should figure it out in
  most cases.

- The little "animated train" buttons for "later" and "earlier" are irritating;
  why not just have arrows? Then it's always clear at a glance what the buttons
  do. 

So, just to prove I'm not just a whinger, I've done a usable redesign of the
timetable form, which addresses some of the points above. Obviously it's not
polished, but I hope it can give you an idea of what a better interface might
look like. You can find it here:
http://www.gerv.net/usability/timetable.html

Hope that's helpful,

Gerv