SQL Server 2008 :: Complex Mode (average) Calculation

I've been asked to find the Mode of the loads on trips we run. So I run a count on the [loads] (without grouping, in an analytical function) column, then sort on the highest counts. The problem is when there is a tie. In that case, I need to find the mean of all the tied values. This means that if there is no mode at all, it would simply take the mean of all the values.

Here is sample data:

CREATE TABLE test6
(
trip char(1) NULL,
date int NULL,
loads int NULL

[Code] ...

And here is what I'd like to see:

CREATE TABLE test7
(
trip char(1) NULL,
loads int NULL
)
insert into test (trip, loads)
values ('A', 15)
insert into test (trip, loads)
values ('B', 17)
insert into test (trip, loads)
values ('C', 11)