Questions about Zazi's plan

NY Times:

...

Even in Mr. Zazi’s case, veteran counterterrorism investigators who regard it as significant acknowledge that important facts remain unknown. Unclear are whether Mr. Zazi had selected a target or a date for a bombing or had recruited others to help.

Moreover, it is not understood fully whether he had built an operational bomb, officials briefed on the case said. Nor is it known why, after practicing with explosive recipes in Colorado, Mr. Zazi drove to New York without chemicals or equipment, the officials said.

...

The Colorado practice run is not that surprising. He could have been doing a "wet" run on the mixing of the explosives to be more efficient when he got to New York. Once there he could approach the same types of sources for material and assembled it near his target. I don't think most terrorist would take the chance of traveling halfway across the country with a bomb. There are just too many opportunities to get caught or have something else go wrong.