Heat transfer efficiency/capability. better. less. Ethylene glycol has superior heat transfer efficiency due to lower viscosity - but more fluid must be circulated to transfer the same amount of energy since Propylene glycol has higher specific heat. Viscosity.
Rotaries, still in use in some parts of the country, are typically larger circles through which vehicles move at higher speeds, while neighborhood traffic circles are typically smaller than roundabouts, and used primarily to calm traffic. In a roundabout, there is no need to change lanes to exit, and traffic moves in a counterclockwise direction. A roundabout also has geometry that forces slower speeds and features islands at the approaches and yield signs. Here are instructions from the Federal Highway Administration on how to use a roundabout:
Less expensive. The cost difference between building a roundabout and a traffic signal is comparable. Where long-term costs are considered, roundabouts eliminate hardware, maintenance and electrical costs associated with traffic signals, which can cost between $5,000 and $10,000 per year.oundabouts reduced injury crashes by 75 percent at intersections where stop signs or signals were previously used for traffic control, according to a study by the Insurance Institute for Highway Safety (IIHS).