The rules are actually set by the states, so may differ from state to
In California, all trailers first registered since 1966 and over GVW of
3000 pounds must have brakes on at least one axle, and have a breakaway
device capable of stopping and holding the trailer for 15 minutes if it
becomes separated. The brakes must be effective enough that the
combination of tow vehicle and trailer can stop within 40 feet from 20 mph.
Check out http://www.dmv.ca.gov/pubs/98vc/vc/tocd12c3a1.htm
However, a single axle is allowed to carry up to 20,000 pounds, which
should be more than enough for a car trailer. Dual axles do have benefits
though, such as smoother ride and (usually) lower ride height. There is
also a range of weights where dual axles can be less expensive (car and
light truck tires are a lot cheaper than big truck tires). Backing up a
smaller dual axle trailer can be tricky though, since the turning radius
changes depending on which tires are slipping sideways.
I believe there was an article in Trailer Life some years ago that
concluded the electronic controls were okay, but the hydraulic sensing ones
were still best (smoother, more predictable on hills, etc.). Of course,
the technology may have improved since then. YMMV
On Tuesday, April 13, 1999 6:43 AM, Tim Mullen [SMTP:Tim.Mullen@trw.com]
> >>> firstname.lastname@example.org 4/12/1999 11:00:00 PM >>>
> Regarding the single axle utility trailer, I guess I just want to do it
> safe and legal. I was under the impression that two axles with brakes on
> both was necessary to meet these requirements.
> For what it's worth, when I bought and then registered my single axle
trailer about 8 years ago, it was explained to me that 3000 lbs gross
vehicle weight is the magic cutoff. If the trailer is rated at 3000 GVW or
more, the DOT requires brakes; 2999 GVW or less, no brakes are required.
I've used my 2900 GVW rated trailer to pull my Elan around the country
when I've moved. 1000 pounds of trailer, and 1600 pounds of car fit nicely
within the 2900 GVW (and the axle is rated for 3500 pounds anyway...)
> But I'd still like brakes. Anybody use the "new" electronic brake
controls? No actual connections to the brake system is required. They
must use accelerometers or something. I wonder how they work...
> Tim Mullen
> 72 Elan Sprint
> 91 Jackson single axle flat bed utility trailer