Horizontal pipe size for kitchen and laundry

[Rocknroj]

I am wondering if I should upsize an existing 2" horizontal (ABS), nicely pitched that serves both my kitchen and clothes washer.. There is a new 2" wash machine drain. 1 1/2 kitchen, running horizontal then connected
to a 2" line that runs about 30 ft before connecting to 3".

based on fixture units i realize that the 2" is fine. As a matter of practice should the 2" be upsized to 3"? Or is 2" better than 3" for keeping the pipe clean?

thanks in advance

 

[Terry]

Washington State with UPC code is okay with 2" for a sink and washer.
Some codes like to see 3".

Sinks are 2" with a 2" cleanout and 1.5" for trap and vent.