Where you might drop off would be dependent on from which direction you are approaching but I accept that in a lot of cases this is going to lead to an extra walk of over 100 metres.
However, your case, in which you would require assistance at one end of the journey and have someone available to give you similar assistance at the other end, is likely to be quite rare. In practice, the majority of people with disabilities would be able to walk or wheel this distance both at the beginning and end of their journeys as long as it was step free.
One the decision was taken to remove the slip road at the front of the station, which it seems to me was done for perfectly sound safety reasons, this less than satisfactory outcome for people with disabilities is inevitable. I don't see how you can argue that queueing traffic outside the station wouldn't be an issue — the usage of Ealing Broadway is set to rise considerably and many of the people dropping off wouldn't be disabled. There is only room for three or four cars at the front so tailbacks would be inevitable.
No one is pretending this new configuration isn't a big step backwards for disabled people in Ealing. The lack of option to drop off nearby reduces the benefit of step free access at the station significantly. However, most disabled people will use public transport or taxis and if it is absolutely impractical to get to a station without the use of a car there are other Elizabeth line stations a short drive away.
Gordon Southwell ● 1204d