Well, I have made a bit of a mistake. That's what happens when you're new to GM-ing, but never fear, I have a way to fix it. That involves actually explaining what I want and then putting it on the OP.
So, the way I want to houserule travel times and preparation was to simply roll it into one post and roll. Simply put, I like to bunch them together in one roll I call the Preparation Roll. It's works simultaneously as a Navigation roll and a pseudo-Initiative roll. Note that I have been keeping track of the time. Simply put, this is my way of implementing "turns". What you roll will determine when you get prepared and arrive there. This should be an OOC roll, so it means your following post will be based on what you roll after I tell you what time you arrive. The caveat to Preparation Roll is that when I ask you to roll it, then it's a signal that you will be on standby until you have arrived. I'm doing this because (I think) it'll keep the plot rolling and we won't have to spend time explaining every single encounter that happens. I will tell you when something unexpected does happen, so do not worry.
The second thing I want to add is that if I ask you to roll something without a threshold indicator, then you don't need to worry about thresholds outside of getting glitches/critical glitches.
@Silence
So I goofed by asking you to roll IC. But you don't have to re-roll or delete your post. In fact, I want you reroll the same Navigation test, as this time it will determine when you arrive. I'm still going to keep that critical glitch into account though because I think that is hilarious and I want to do something with it. What it will be...well, you'll see.
@Jack
Roll for Preparation: Navigation + INT
@obidancer & Wrong
Both of you roll a Perception test: Perception + INT[Mental]