Watch the incessant flow of unorganized Paris traffic at this intersection a few blocks from le Louvre: pedestrians, cyclists, motorcycle riders, cars, taxis, buses… and the lack of traffic controls such as road markings, signs and lights.
Also note the frequency of what Americans would consider dangerous activity: bicycling in dress shoes (often heels), using mobile phones while riding, carrying packages by hand or loose in baskets, even smoking. And certainly no helmets or cycling-specific equipment like clip-in shoes or skin-tight clothing. Finally, notice the absolute lack of conflict and apparently nil perception of danger to the vulnerable road users. (Once you stop flinching…)