What is the preferred plural form of "bus"?

The OED states that both "buses" and "busses" are acceptable plural forms of "bus". Is one generally preferred over the other?

Solution 1:

To be more precise, the citations in the OED’s entry for bus include 2 instances of busses and 9 of buses. In its own commentary, the OED uses buses. The British National Corpus records 1438 instances of buses and 10 of busses. The figures in the Corpus of Contemporary American English are 5139 and 116. I think that means you’re in good company if you use buses.

Solution 2:

As others have pointed out, buses is far more common than busses.

But I see no mention of the fact that in recent decades, busses is almost exclusively restricted to the computer hardware context, where a bus is a subsystem that transfers data between components inside a computer. For reasons that escape me, buses rarely occurs in the computer context.

EDIT: I'll just add that I worked for decades on computerised systems within the UK public transport industry. Until this question came up I don't think it ever occurred to me that anyone might switch or merge what I'd always thought of as two completely distinct words. But I did sometimes wonder why the computer singular wasn't always spelled buss (as sometimes it was).

Solution 3:

Google NGram Viewer shows that buses is more popular than busses.