This exists in many cities. See Bus Rapid Transit and many rail lines. Seattle's network has many instances of this.

Seattle has instances of it, but there are still many parts of the city not well connected by transit.

	▲	buuyytp 39 minutes ago \| parent [-]
		That's a different goal post. The original claim was: "If only most cities could have this today" Seattle has this. No one claimed or required it to be universal within the city.