Garmin GPS: Dead Reckoning feature lacking in Nuvi 3-- series?

"Ken" <net> wrote in message
news:com 

Dead reckoning is the ability to continue auto-routing if the unit loses
satellite lock, say when you enter a tunnel. It requires a physical
connection to the vehicle's speedometer system. I don't know the Nuvi
units but the comparison that I do know is the difference between the
StreetPilot 2610 and 2650.

Ivor

Ken wrote: 

Based on my exprience with nuvi 350, there's some kind of poor man's
dead reckoning feature in the SW as the unit shows a moving map in most
of Boston's Big Dig tunnels, even in the 1-mile long Williams Tunnel to
Logan, but somehow not in the old Callahan Tunnel; it's puzzling, but
that's what I've seen many times... I don't believe there are any
transmitters in the tunnel, so the unit must assume that the speed will
not change for some time...

z.entropic

z.entropic wrote: 
Thanks.

Ken K

On Fri, 02 Jun 2006 07:21:32 -0700, Ken <net> wrote:
 

I googled dead-reckoning and found several items.
Among them is this. I learned something too. . .

http://en.wikipedia.org/wiki/Dead_reckoning

Antenna Erector wrote: 

Nuvi has quasi dead reckoning. It will assume your same heading and speed
for 30 seconds.