[RFI] Strange radio static problem in vehicle

[Richard (Rick) Karlquist]

My van has a very strange radio static problem 
observed on the AM BCB radio.  If I drive along
a road next to a high voltage power line, I get a bunch of 
static in the AM radio.  However, this static
only occurs when I am moving.  If I stop and 
even park under the lines there is no static.

Furthermore, if I drive along roads with ordinary
power lines, there is no static.  For these purposes,
"ordinary" power lines are ones with only a few
disks on the insulators.  "High voltage" lines
have 8 to 12 disks.

This phenomenon is very repeatable and consistent.

Any ideas what is going on here?

Rick N6RK