How to find the best same-day hotel deals

— -- Procrastinators, take heart. If you are fueling up the car this summer for a road trip and haven't booked your hotels yet, you can try several new mobile apps and a website to find tonight-only hotel deals that may land you some attractive discounts.

For example, if you had been tooling around Orlando on Tuesday, you could have used the Priceline Hotel & Car Negotiator app to find a Tonight-Only deal at the 3.5-star Rosen Plaza Hotel for a total rate of $60.54, including taxes and fees. The same room at the property was going for $166.83 on Expedia.com.

But you need to comparison shop because a "deal" isn't always a legitimate bargain or the amount of actual savings compared to an advance booking may be exaggerated.

Booking.com, Hotel Tonight, Orbitz and Priceline are among the providers of these tonight-only, or same-day, hotel rates. And with these types of deals, you always know the name of the hotel and the rate in advance, as opposed to "opaque" booking sites where you bid on undisclosed properties.

The way it generally works is that you can use their mobile apps and, in the case of Booking.com, its website, too, to secure sometimes-substantial discounts for stays for that same evening. In some cases, depending on the property, you can extend the stay and the rate for subsequent nights.

Hotel Tonight, Priceline and Booking.com load their same-day rates about midday local time, and usually for a select number of properties with which they have negotiated special deals.

For example, if you pull the car over at a New Jersey Turnpike rest stop at 9:05 a.m. and want to get a head start on searching for that night's room in New York City, you might see the following message from Hotel Tonight:

"Aren't you the early bird? Hang tight. Today's deals will be available at noon NYC-Downtown time. Come back then, or stay here and watch the timer count down. It's like New Year's Eve, but you get an awesome deal instead of an awkward kiss."

Then you'll see a digital timer count down from 2:55:00 until that night's hotel deals are ready for your perusal.

Same-day hotel-booking is definitely not for everyone. If your road trip means you have babies in car seats or pre-teens playing video games in the back seat, you'll probably want to book your hotel stays well in advance so you have the security of knowing where you will be sleeping and if you have a room for that evening.

What's more, these tonight-only hotel-booking features tend to be in big cities and available mostly during non-peak periods. So if you are traveling through Yellowstone National Park in July, they are not your best options.

Furthermore, in the case of Hotel Tonight and Priceline, for instance, you can't guarantee the room type you'll get when you show up to check in, so that is a drawback for some guests, as well.

Still, if your hotel choices are flexible, you can find some compelling deals at everything from run-of-the-mill to trendy and upscale properties. It's one occasion when being late may even pay off.

Here are the main tonight-only hotel offerings covering the USA:

BOOKING.COM TONIGHT

(free, available on iOS and Booking.com website)