Along with standing around at a gas station watching your last paycheck click away before your eyes, parking has to be one of motoring's less pleasurable pursuits.

Just like filling your car though it's a necessary evil, so in the absence of doing away with it completely, anything that makes it easier is certainly worth a look. A new app by San Francisco-based startup Streetline could do just that.

Streetline's system is a form of "smart parking". Using technology that can be fitted to parking spaces, sensors  can tell when a car is occupying the space, allowing the system to track empty and occupied spaces in real time.

Linking this data with a smartphone app then allows anyone looking for a space to see where the nearest unoccupied space is, saving them doing laps around the block looking for the nearest empty parking lot or spot on the street. Users can download the free Parker app to let them know of free spaces nearby.

This saves time for you as a driver, money for you as a consumer and reduces fuel consumption and emissions to satisfy the environmentalist in you. A study at UCLA by Donald Shoup, a professor of urban planning, monitored 15 city blocks in Westwood Village, L.A. The average driver spent 3.3 minutes looking for parking spaces, and circled the block two and a half times.

Over the course of a year the cumulative effect for all those drivers was an estimated 47,000 gallons of wasted gas, 950,000 wasted miles and 730 tons of CO2. And remember - that's just one neighborhood in one city.

Streetline is selling its small, battery operated sensors to cities, universities, hospitals and shopping centers to help reduce their parking problems. Businesses in Hollywood and Studio City in L.A. and Metro stations in Washington, D.C. and downtown Asheville, N.C. have all put the systems in place so far. The system is also live in the Marina neighborhood of San Francisco, but there are plans to expand it to other Bay Area cities too.

Streetline's Parker isn't the only system helping drivers park. The San Francisco Municipal Transportation Agency's SFpark project uses wireless parking sensors in areas such as Fisherman's Wharf and Fillmore that allow parking meters to vary rates depending on parking demand, and the information is available in real time via the free SFpark iPhone app.

SFpark covers 7,000 of the city's 28,800 metered spaces and over 12,000 spaces in three quarters of SFMTA-managed parking garages.

With the number of cars on the road expected to rise from 800 million today to at least 2 billion by 2050, traffic levels in cities are expected to increase massively. It's difficult enough trying to find somewhere to park at the moment and even more so in cities like Beijing, where the traffic increase is likely to be greatest as China becomes more and more mobile.

Parking apps and connected systems using GPS and real-time data are likely to become increasingly vital as time goes by for those who don't wish to spend as much time trying to park each day as they spend at work.

[Mercury News]