Luckily there is a solution. Purchase a 2GB (or larger up to 16GB) High Speed MicroSDMC memory card (8GB $20 at BB).
Follow these four steps:
1 - Download the large (771MB) Junction View file D3060030A.JCV (see link below) for Map version 2012.20.
>> Edited Nov 2011:
>> Map update (2012.30) requires Junction View file (D3060040A.jcv).
2 - Create a Garmin\JCV folder on the Micro SD memory card and copy the D3060030A.JCV file to it.
3 - Hook the Garmin GPS to your PC and open up Windows Explorer and look for the system\JCV folder in the internal memory (you will have to enable viewing of hidden and system files in Windows Explorer).
4 - There are one or two smaller JCV files in the folder (I had two: D3178000A.JCV and D3178010A.JCV). Change the name of both files by adding a ".disabled" to the end of the file name to disable them. The GPS will first look in the internal memory then automatically scan the micro SDHC memory card looking for the JCV file.
When you restart your Garmin 1450/1490, the full set of Junction Views will be there. You can run a few GPS simulations through a major city and watch them pop up. Before I made this change I could not find a single one in Philadelphia. Afterwards I found 10 straight away just by simulating some of my favorite routes that pass through the city. This is really a cool feature.
Here is the link to the detailed instructions that also includes the URL to the large Junction View file. Hopefully the moderators will not remove it. http://forums.gpsreview.net/viewtopic.php
This super-large Junction View file only works with the latest NA map revision 2012.20
BTW - I recommend a Class 10 speed micro SDHC memory card. I didn't try a Class 4 (or lower); however, I suspect that a slower speed memory card could cause a delay in bringing up the Junction View image as you approach an interchange.