I have found the only way to discourage the cart drivers from playing chicken with me is to 'talk car' to them. The discourteous cart drivers are the SUVs of the multimodal paths but everyone of them fears a car.
You reach into the cart drivers inner fear by using automotive horns (for bikes). Loudbicycle makes these.
Loud Bicycle | Car horn for bikes.
They have two models, the 'mini' which is two diaphragm horns, hi and low pitch. This sounds like a midsized Toyota. Or the 'classic' snail horn, sounds similar to a 1998 Buick LeSabre. Neither model is suitable for cyclists that count bike accessories by the gram, or penny pinchers.
I have both, they have saved both myself and Mrs. Toymeister from non-attentive car drivers and the aggressive cart drivers. Frankly, it snaps the cart drivers out of their aggressiveness like a dog on a shock collar. They can't comprehend that a bike can sound like a car.
For the bike horn haters: if you heard mine you were doing something incredibly stupid!