Two traffic signal systems are being considered for an intersection. One system costs $34000 for installation and has an efficiency rating of 80% requires 30 kW power (output), incurs a user cost of $.21 per vehicle, and has a life of 12 years. A second system costs $42000 to install, has an efficiency rating of 91%, requires 32kW power (output), has a user cost of $.23 per vehicle, and has a life of 18 years. Annual maintenance costs are $74 and $100, respectively. MARR=8% per year. How many vehicles must use the intersection to justify the 2nd system when electricity costs $0.11/kWh? Assume salvage value for each system equals zero. Project the difference in the user cost as savings for the second system. There are approximately 8760 hours/year.

At least what number of vehicles per day must use the intersection to justify the second system?