Travel by road in Johannesburg is medium to high risk. The standard of driving is poor, with many drivers insufficiently trained, uninsured and unqualified. Due to the low driving conditions, traffic can become congested in most major cities, including Rio de Janeiro. High volumes of traffic present a dangerous threat to travelers from opportunistic criminals in the area. Major roads that handrail or dissect through favelas are hotspots for criminal activity and western travelers are at increased risk.