it all depends....for example, it takes me 20 minutes to get home from the airport if there is no traffic....in peak hour traffic it usually takes me about an hour....but there have been times where its taken me 2 hours as well during peak hours....

Thanks, this is helpful.

As big a deterrent as the extra traffic is, it seems like the lower risk involved in a non-stop plus the times savings in a non-stop vs. connecting light leans me towards biting the bullet.

Is there a time when you think the traffic dies down on a Friday night?

after 8:30-9pm....

I don't want to open a new thread, so I will just ask here.

So, what is the best way from Mumbai to Agra? Is there a direct train?

There are direct trains, they take anywhere between 17 to 21 hours. If you have that much time, perhaps with an overnight train, then it may work out.

Otherwise I'd take a flight to DEL and take a cab down to Agra.

Thanks, well that would be much more convenient than spending an entire day in a train.

It's not quite that bad, but I admit that I have only done the reverse direction, ie Agra to Mumbai.
We boarded the train in Agra at 2pm, a overnight 1st Class Sleeper, and arrived on time in Mumbai at 8am next morning. Very convenient timing, with the afternoon downtime no worst than checkin/checkout time at the airports. Also very happy with the train ticket price - near a $100 as I recall.