Roundabouts are compact, traditional traffic-management hubs. They are targeted at helping congestion situations, including heavy rain. And since they are already built into many city streets — rather than new construction — they don’t tend to build themselves into the street any more than a highway would.
Signals along urban roads were built to identify the two most traveled intersections. But many cyclists, motorists and pedestrians want signals to indicate the intersection to those who want to enter and depart — and cyclists want to avoid being impeded while walking through traffic. So while it is always useful to improve signalization along major intersections, the best signalization technique for maximizing travel-time savings is the easy one: slowing down.
The “safe right turn” signal, which triggers a slowing down to a very gradual speed, becomes very popular with cyclists, allowing them to avoid accidents that many use for their commuting times, while still pushing them through intersections.