With $3-plus gas prices as the new normal, traffic showing no signs of slowing while parking shortages are on the rise, driving can be as expensive and stressful as ever. Fortunately a number of handy car apps can save you time, money and maintenance. And they’re all free. Here are the top five: 

GasBuddy: True to its name, GasBuddy searches out the cheapest gas stations in your vicinity based on your location or by plugging in city/zip/postal code. This app relies on its user community to chime in on discrepancies and station details, all in the spirit of banding together to combat high gas prices. As with airline miles and credit cards, you can earn points and awards by participating (read: win free gas). The app cannot always distinguish between cash and credit prices, however, as many gas stations charge additional fees if you use a credit card. 

MetroMile: MetroMile monitors your driving stats in order to make better road decisions. You can figure out the best times for the fastest commutes and plan gas-efficient routes, check engine status, and receive reminders of where you parked. For this app to work, however, you’ll have to order a Metronome, a gizmo that plugs into your car’s diagnostic port under the dashboard (available in California, Oregon, and Washington to drivers of post-1996 vehicles, free of charge). Some reviews claim the stats are unreliable, so this app may be a work in progress. On its site, MetroMile sells insurance based on the number of miles driven, aimed at drivers who log in less than 10,000 miles a year. The app is available only on iPhone, iPad and iPod touch.

Trapster: No more relying on flashing headlights from approaching drivers, thanks to this popular app that provides advanced warning of—you guessed it—speed traps, including red-light cameras and live speed traps. Much like a wireless radar detector, Trapster scans reports and provides updates using your phone’s GPS. On most phones, these speed traps are displayed as icons on a map. Users can also share a crowd-sourced database of traffic jams, accidents, construction zones, and other hazards.

aCar: Similar to MetroMile, aCar bills itself as a one-stop shop to track fuel mileage, fill-ups, maintenance and other expenses. Based on your vehicle specifications, the app will alert you with service reminders and store receipt details afterward. It can link to multiple vehicles simultaneously, including trucks and even bikes. The app is free but offers an upgrade to Pro ($5.99). The premium version includes translations to other languages, full-screen charts, quick access to home screen widgets, and data import/export to and from other apps and online accounts such as DropBox and Google Docs. Available only for Android, Amazon Kindle Fire, and BlackBerry devices.

BestParking: If you depend on parking lots and garages, or you’re tired of event parking rip-offs when you’re out on the town, then this app’s for you. BestParking searches out the cheapest parking in your area and can also provide contact info, hours of operation, discounts, and the scoop on whether the facilities accept cash or credit, and if they offer valet service. Geared to urban drivers, the app is only available in just over 100 major cities between the U.S. and Canada. Check the site for a complete listing.

The last mile: It should be obvious, but there’s no need to use these apps behind the wheel. Use them before and after your excursion, or pull over if you’re in a pinch. The last thing you want to do is get pulled over for driving while app’ing.

What’s your favorite car app, and what makes it stand out from the pack?