Modern roundabouts are the safest form of intersection in the world. Search IIHS for FAQs and safety facts.
The first cost of any two choices is a poor way to compare. Life-cycle cost is the best (present value of future costs, a.k.a. net present value). When comparing modern roundabouts to signals for a 20-year life cycle (the standard period), modern roundabouts usually cost us much less. Costs to compare include: first cost (design/land/construction), operation and maintenance (electricity, re-striping, etc.), crash reduction, daily delay (what’s your time worth?), daily fuel consumption, pollution (generated), area insurance rates (this costs more where it is less safe to drive). Each of these things, and others, can be estimated for any two choices and everyone near or using the project area will pay some portion of all of these costs.
More info: http://tinyurl.com/739pu3d
9 months ago