How about this:

--== TEST DATA ==--

declare @data as table

(

CustID int,

ProdFamily varchar(15),

Route tinyint,

#ofStops int

);

insert @data values (10001, 'Dairy', 101, 14)

insert @data values (10001, 'Dry Groceries', 101, 14)

insert @data values (10001, 'Meat', 101, 14)

insert @data values (10002, 'Dairy', 101, 15)

insert @data values (10002, 'Dry Groceries', 101, 15)

insert @data values (10002, 'Meat', 101, 15)

--== SUGGESTED SOLUTION ==--

select CustID, ProdFamily, Route,

case when Row_Number() over (partition by CustId order by ProdFamily) = 1 then #ofStops else 0 end as [#ofStops]

from @data