As many of you are requiring Joe's research materials, I asked Joe's approval for sharing his presentation slides.  Here it is:

ftp://ftp.camsys.com/temp/outgoing/CTPP/JoeSakshaug_Synthetic.pdf

Liang Long
Cambridge Systematics, Inc.
4800 Hampden Lane
Suite 800
Bethesda, MD 20814
tel  301 347 9141
fax 301 347 0101
FHWA 202-366-6971
e-mail  llong@camsys.com
www.camsys.com