I don't rely on random encounter tables for much more than inspiration or flavour, and I don't see travel as just the thing that happens between adventures. It's prime real-estate for encounter design. You can expose so much of the campaign and its themes to the players by building encounters that illuminate their own goals and the goals of their enemies. Later, they're going to be teleporting and plane-shifting around like crazy, IMO you *need* to use those early levels effectively if you want to build a memorable campaign!
I agree, I believe in setting the setting. Heh. The atmosphere, culture, the current state of affairs. I ran a home campaign a couple years ago where the characters didn't know it, but they encountered giants early on sending a gift to the Lords Alliance a massive Crystal statue. The statue was actually a magical artifact crafted by fire giants that required strategic placement in Neverwinter. The PCs not wanting to piss a giant off at early levels decided to help protect the giants from crazy wild protestors... Druids and rangers and others that had deduced there was a negative aura of the crystal. (One of the players was an evil warlock, and in the players defense they had to pick a side and sided with the giants). And had the crystaline statue delivered to Neverwinter and placed outside the castle. Well the campaign ended due to a player moving away and just not having enough players.
I started back up with hoard of the dragon queen with 2 of the same players. So I set the setting about 400-500 years after the delivery of the crystal. The world had experienced a massive famine along the swordcoast, causing a huge die off of the population and allowing age old groups like the cult of the dragon to finally get a foot hold on the sword coast. Plus, it was infamous heroes that delivered the crystal that caused the massive withering and dieoff of vegetation to act as a magical battery. Eventually Clerics realized what was happening and were able to shield the crystal so it was no longer sucking energy from the land. But, politics being what they are, all heroes were rounded up and imprisoned and/or executed in an effort to find the ones that delivered crystal in the first 100-200 years. After that, 200 years later, the tensions died down as the land started to recover.... slowly, and now in this campaign the sword coast is starting to thrive but the cult took this time to really foster anti - hero sentiment. So, level 1 the PCs were in the process of realizing they displayed some heroic abilities and were becoming outcasts in their villages and/or towns and had heard rumors of Greenest being Hero friendly, but there were military patrols out still keeping eyes out for any demonstrations of heroic abilities and arresting them if they didn't have a permit to wield magic items, or some type of certification from wizards guilds stating their use of magic was lawfully authorized and/or approved by the wizard council. Which, led them to them running into an occasional patrol or even a flat out arrest where Leosin had to jump and aid them with the Harpers help.
This created the setting that they rarely wanted to travel by road, and they had to be alert day and night for potential patrols, and/or assassins. Plus, investigate what's happening with the cult.
It really set the mood for how the roads, people, and general trust / sentiment of heroes all dressed in clean magical armor, big and powerful weapons, and at times shop keepers just wouldn't talk to them... Or shop prices were extremely inflated for them... by 10 times or more for typical things.
It's led to some interesting and even unplanned challenges and directions in the story and affects everything they. Now, though they have write from the Lords alliance indicating all heroic activities they are doing are for the lords alliance on private matters with the seal of the lords alliance. So a lot of that goes away, but it's still there.