I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

On May 17, 11:41*pm, "Al Lorona" wrote:
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact"..
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

Maybe for interstates but I have seen some overpasses that were lower
than that.

Jimmie

On May 17, 8:41*pm, "Al Lorona" wrote:
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact"..
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??


It's not a rule about antennas per se, it's maximum height of
vehicle. In California, it's 14 ft (with some special exceptions).
CVC 35250. No vehicle or load shall exceed a height of 14 feet
measured from the surface upon which the vehicle stands, except that a
double-deck bus may not exceed a height of 14 feet, 3 inches. Any
vehicle or load which exceeds a height of 13 feet, 6 inches, shall
only be operated on those highways where deemed to be safe by the
owner of the vehicle or the entity operating the bus.

There's also a federal rule for interstate highways that, in effect,
says that if your vehicle is less than 14 ft high and 8 ft wide, it
will fit on all interstate highways (if there's a low bridge, you'll
have the get off and go around path marked.

CVC 35100. (a) The total outside width of any vehicle or its load
shall not exceed 102 inches, except as otherwise provided in this
chapter.

(b) Notwithstanding any other provision of law, safety devices which
the Secretary of Transportation determines to be necessary for the
safe and efficient operation of motor vehicles shall not be included
in the calculation of width as specified in subdivision (a).

(c) Any city or county may, by ordinance, prohibit a combination of
vehicles of a total width in excess of 96 inches upon highways under
its jurisdiction. The ordinance shall not be effective until
appropriate signs are erected indicating the streets affected

In article ,
Al Lorona wrote:

I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

I don't think there's a maximum antenna height, per se. However,
there are some standards for the minimum heights of bridges and other
overpasses.

Take a look at

http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm

Specifically, section 7A specifies that sections of the Interstate in
rural areas must have a clear height of not less than 16 feet, while
some Interstate routes in urban areas can be as low as 14 feet.

I believe that the "13-and-a-fraction foot" height is intended to
ensure that the vehicle can pass along all conforming Interstate
routes without hitting anything... it's a comfortable margin below the
14-foot urban minimum. I've heard "13 feet 9 inches" as well as the
"13 feet 6 inches" figure you mention.

There are some exceptions: Interstate overpasses below the specified
minima. See

http://www.aitaonline.com/Info/Low Clearances.html

for lists.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Al Lorona wrote:
... and the state with the lowest height limit would then
become the 'national standard'??

The maximum allowable height rule for the CA
mobile shootouts that I attended was 12.5 feet
from the ground. Don't know if that's the CA
limit or not.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

13'6" sounds close. If I needed to know I'd check the maximum height of a
semi-trailer on the hiways and it's probably a standard for a least 48
states.


"Al Lorona" wrote in message
...
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50
separate state standards, and the state with the lowest height limit would
then become the 'national standard'??

Cecil Moore wrote:
Al Lorona wrote:
... and the state with the lowest height limit would then
become the 'national standard'??

The maximum allowable height rule for the CA
mobile shootouts that I attended was 12.5 feet
from the ground. Don't know if that's the CA
limit or not.

CA limit is 14 ft (unless you have a "moving permit")
Pilot cars can have a measuring device that's taller, as long as they
don't go slower than 20mi/hr below the speed limit. (presumably this is
in connection with the moving permit for the oversize load that's following.

Your friendly local CHP office will work out the route for you..

"Dave Platt" wrote in message
...
In article ,

Take a look at

http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm


Thanks, Dave, for the exact reference sites. They were helpful. And thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in Altadena
and found that there really is no right answer. The guy at the front desk
said that the "consensus" in the office was 14 feet. And of course he was
speaking only for California. He said that there's no separate regulation
for antennas, only the number for total vehicle height. There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

As you saw, the replies to my post ranged from 12.5 to 14 feet. It surprises
me that the standard deviation implied by this spread is that large.

All in all, this has been very surprising.

Thinking about it some more, perhaps the limiting factor becomes not bridges
and overpasses, but fast food drive-thrus and gas station roofs.

Al Lorona wrote:
I just called the California Highway Patrol office in Altadena
and found that there really is no right answer.

For one of the CA 75m shootouts that I prepared for,
I had a white PVC pipe extending up about 9 feet from
the tool box on my pickup. I was stopped by a Maricopa
County deputy sheriff who tried to give me a ticket
for violating some height limit.

I demanded that he put the law section number that I
was violating, on my ticket. After spending about an
hour on his radio, he couldn't do it and let me go.

To be truthful, I had outrun this guy on my Z1B Kawasaki
motorcycle and he was itching to give me a ticket. :-)
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Al Lorona wrote:

"Dave Platt" wrote in message
...
In article ,

Take a look at

http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm


Thanks, Dave, for the exact reference sites. They were helpful. And thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in Altadena
and found that there really is no right answer. The guy at the front desk
said that the "consensus" in the office was 14 feet. And of course he was
speaking only for California. He said that there's no separate regulation
for antennas, only the number for total vehicle height. There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

As you saw, the replies to my post ranged from 12.5 to 14 feet. It surprises
me that the standard deviation implied by this spread is that large.

All in all, this has been very surprising.

Thinking about it some more, perhaps the limiting factor becomes not bridges
and overpasses, but fast food drive-thrus and gas station roofs.


And parking structures.

Don't even think about going to Vegas with an antenna much over 8 feet
tall unless you plan on parking in the back 40 with the RV's.


--
Jim Pennino

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