I think the 10,001 is for interstate, not intrastate. At least that's what I believe it is in CT. If I go to MA to clean someone's gutters with my 12,500# GVW Ram 3500 I would require DOT numbers on the truck. Not sure what else I would have to comply with though, logs, med card etc.
If I stay within state borders I don't need DOT number.
JB.
JB, according to this CT has adopted the same regs for intrAstate commerce.
What is a USDOT Number? - Federal Motor Carrier Safety Administration
That said I know that link has errors in it. IIRC CT has adopted the regs but revised it to start at 18k instead of 10k.