For travelers planning to hit the road this weekend, having a smartphone in hand can help with tasks as varied as finding the nearest clean bathroom, securing help for a flat tire and quelling the backseat cries of Are we there yet?

AAA anticipates 28 million drivers will be on the road over Memorial Day weekend, a 5.8% increase compared with 2009. Consumers on road trips account for 87% of the total 32.1 million people expected to travel over the holiday.

Those travelers will find plenty in the growing app market to fit their travel needs. Now that we re two years into this app phenomenon, we re seeing lots of niche offerings, says Brad Spirrison, the managing editor for Appolicious.com, an app review site. Developers have come up with apps specific to your destination, vehicle model and other individual travel needs.

The National Highway Safety Traffic Administration recommends drivers keep their eyes on the road and away from the phone, so entrust app manipulation to a passenger. (With so many free downloadable games, the phone can also be a great source of entertainment to kids.)

Check out these six that Spirrison, other app experts and veteran travelers rely on:

1)

Free
Available for: iPhone

Sure, there are plenty of navigation apps out there, but AAA s new offering does it for free, says Doug Newcomb, the senior technology editor for car-data aggregator Edmunds.com. Travelers don t need to be AAA members to take advantage of the features, which include turn-by-turn voice directions and maps of AAA-approved hotels, restaurants and other business and attractions along the route. The app also taps into AAA s gas-price monitoring to show nearby stations latest prices.

However, if you want GPS-enabled roadside assistance from AAA, you need to pay the $58 to $88 a year membership. They already have information about your vehicle [model and repair history] and your exact location, Newcomb says.

2)

Free
Available for: Android, BlackBerry, iPhone and Palm Pre

The two developed an iPhone app called State Lines Yelp app users can search venues by category, or check out nearby restaurants, bars and other businesses on a map, with reviews and star ratings for each. The app relies on user contributions, so entries may not be heavily reviewed in less-traveled areas.

Free
Available for: Blackberry and iPhone

When you ve got to go, you ve got to go -- preferably somewhere clean. This user-driven app offers reviews of public bathrooms, searchable by zip code, intersection or locations near your phone. The app also notes which locations are currently open or closed, if the store hours are known. Because it relies on user contributions, coverage may be spotty or outdated in less-traveled areas.

4)

$2.99
Available for: iPhone

Plenty of free apps will tell you which businesses are nearby, but iExit groups them handily by freeway exit, Spirrison says. The app also lets users track favorite businesses, so they ll know each time they pass, say, a Cracker Barrel, or can find out how many miles until the next one (it shows up to 50 upcoming exits). If you d rather save the money, AroundMe for the iPhone provides similar (but non-exit-specific) information for free.

5) Auto Manufacturer Apps

Several auto manufacturers are offering free apps with a direct line to 24-hour roadside assistance and other perks, Newcomb says. Drivers get regular updates on when help will arrive, but that can still take awhile based on their location relative to the nearest service center.

* BMW s Roadside Assistance app for Android, BlackBerry and iPhone uses the phone s GPS to pinpoint the user s exact location. Provide details about the car and problem to request service for a lock-out, accident or other problem.

* Mazda s Roadside Assistance app for iPhone lets users request assistance electronically. In an emergency situation, it connects the user with a phone representative and uses data from the phone (GPS location, etc.) to send help fast.

* Mercedes-Benz s mbrace app for BlackBerry and iPhone lets users remotely lock and unlock their vehicle, view the vehicle s GPS location (say, if they forget where it s parked), call for roadside assistance, find the nearest dealership or repair center, or even make a payment.

6)

Free
Available for: Android, BlackBerry, iPhone, Nokia, Palm, Windows Mobile

Get advance warnings of speed traps and red-light cameras along your route, says veteran traveler Amy Graff, who chronicles her family s vacations at OntheGowithAmy.com. The app tracks more than 400,000 user-submitted -- and law-enforcement submitted -- stops nationwide. (Some law enforcement units, including the Travis County Sheriff's Office in Texas, enter their own locations in a bid to get drivers to slow down.) But a warning to speedy drivers: Because the site relies on users to report problem areas, some areas may have more reliable coverage than others.