Hmm guess your right. Learn everyday. I always thought it was illegal, guess I read the text wrong or confusing it with something else. Been close to 20 years since I read the rules.
You will have to get a broker mc and surety bond to broker freight. You don’t have to but liability and cargo insurance for the brokerage is encouraged. Having said that, you can have the trucking mc and the brokering mc as the same company but insurance companies do indeed frown upon this extra risk. I would make it two separate companies so trucking insurance has no reason to care.
You are using the term broker ALL wrong as many here are. Let’s consider you mean you have an authority and direct customers, not scrapping loads from the load boards. You can do this all day long, no problems with the fmcsa. If you are booking loads off a load board under your authority, then seeing if you can find another carrier to take them, that is sub-letting or sub-outing a load and there are legal issues with it. Either way if you have a load booked as a carrier, you can find/hire another carrier to haul that freight and you don’t need a brokers authority to do so. This is done every day by megas and large fleets. FedEx does this and so did others like ceva. why the insurance company is concerned about it? The answer is clear, it is very valid concern. under the law/regulations and court cases, even if you have sub-out the load to another carrier, you and your insurance company is 100% responsible for that cargo. most insurance companies will require you go down the brokers path to cover their butts.
Interlining went away with MAP-21. Not that carriers don't do it, it is still brokering. The mega's and others you listed have broker authority.
Really, where? seriously, the map-21 restricts a carrier from being a broker as define by the fmcsa - a broker is one who “for compensation, arranges, or offers to arrange, the transportation of property by an authorized motor carrier”. When the carrier is engaged to transport the load exclusively, they can sub-out or sub-let that load to another carrier legally as long as the legal and insurance requirements are met. Those carriers who hold an authority as brokers do so to limit their liabilities under the interstate authority they hold. if this wasn’t the case then distressed loads would never get moved by a third party, and that happens every day.