i have a huge set of numbers (trip times from point a to b) most of
the numbers fall into a "normal" range ....occasionally, when there is
a delay, trip times go up for a short period. how do i find the number
that represents a "normal" un-delayed trip?

just a comment:
Depending on what you are using the "normal" number for, I would try
calculating the average

(A+B+C+...+Z)/(# of numbers)

or find the median number by sorting all the numbers from shortest
time to longest time and then finding the middlemost (# of numbers)/2
number:

Calculating a mean and standard deviation for your population would be
most informative.

I have a huge set of numbers (trip times from point a to b) most of
the numbers fall into a "normal" range ....occasionally, when there is
a delay, trip times go up for a short period. how do i find the number
that represents a "normal" un-delayed trip?
 
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The way I read the problem is that you have to 
Step (1) Determine which values are outliers (the delayed time values)
Step (2) reject those from your data set
Step (3) find the average of the rest 

My high school mathematics book suggests that outliers may be either
(A) more than twice the interquartile range from the median; or
(B) more than 2.5 times the standard deviation from the mean (for continuous data).

If you have discrete data such as travel times, 
it might be easiest to use (A) twice the interquartile range.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
An example problem:

If my travel data is
12 13 13 14 15 15 16 18 18 19 24 25 27 43 44 hours

Step (1)
The median = 18 (the middle score)
Q1 = 14 (the middle score of the bottom-half)
Q3 = 25 (the middle score of the top half)

The interquartile range is 
Q3 - Q1 = 25 - 14 = 11

Step (2)
We reject data which is greater than 
the median + 2 * upper-interquartile range
= 18 + 2*11
= 40

We are left with
12 13 13 14 15 15 16 18 18 19 24 25 27 hours

Step (3)
The median of this is 16.

++++++++++++++++++++
Extras
1) If you have an even number of scores 
the median is the average of the middle two scores:
e.g. The median of (1 5 6 9) is (5+6)/2 = 5.5

2) It might be easy to automatically organize the data 
from smallest to greatest using a spreadsheet program.