Arguably the most spectacular day hike in the whites is the Franconia Ridge Loop that consists of two side trails, Falling Waters and Old Bridal Path connecting with the AT on the Franconia Ridge that goes over Lafayette, Lincoln and Haystack. Its a long stretch along treeline right at the top of exposed ridge. Old Bridal path goes up a side ridge which is wooded but a very decidedly steep ridge with views up to the main ridgeline. AMCs Greenleaf hut is also on this trail. Falling Water trail run along a drainage past several large waterfalls. The side trails both start at the same trailhead at Lafayette Place. There are parking lots on either side of the parkway connected by a tunnel under the parkway. There is also a very popular busy state park campground adjacent to the south bound lot(reservation strongly recommended). These lots also have side trails to access the AMC Lonesome Lake Hut and a couple of popular day hikes. For years and pre covid, the lots filled up rapidly but the state looked the other way and grudgingly looked the other way and allowed cars to park along the narrow parkway. The state finally cracked down for a couple of summers on parking along the parkway and set up a paid shuttle from a Cannon Mtn ski area lot. It was last minute affair with the state making up the rules as they went. Covid shut it down for two summers but this year the state is making it permanent and no doubt will be enforcing the no parking along the parkway rule aggressively.

Franconia State Park has posted the rules for the shuttle this year. https://www.cannonmt.com/the-notch/hiker-parking. Note they do not indicate when it will start and there is zero notice at the Lafyette Place lots.
Although there was discussion about putting in a parking fee at the Lafayette lots to subsidize the shuttle that is not indicated in the rules they posted. Folks wanting to park at the lots on weekend need to be there very early before 7 AM. There are a lot of parking slots tied up by AMC hut guests. Folks staying at the AMC huts should take advantage of the AMC hut shuttles so they do not have to park there.

BTW there is debate on whether to go up Old Bridal Path and down Falling Waters or in reverse. My preference is up Old Bridal path as I get earlier views and do not need to carry much water as I can fill up at the Greenleaf Hut. Heading down on hot day I appreciate the waterfaills and water crossings much better. Most people are in rush past the waterfalls if they go up Falling Waters. Others prefer going up Falling Waters as its quite steep and the sun is on their back along the ridge. I also like going up the Old Bridal Path as it gets me up to the highest point on the hike earlier in the day. The summits tend to cloud up early in the afternoon so getting view is more likely this way. If weather is coming in folks can see it coming and worse case head back down the way they came.

Yes parking is PITA but definitely worth the hike.