:Interstate 93 goes through three states and is one article, so the first part of this argument falls on its face.  Looking at statistics (from the page size widget), we can compare this article to some other Interstate articles: 
 :{|class=wikitable 
 |- 
 !rowspan=2|Article !!rowspan=2|File size !!colspan=2| Prose size !!rowspan=2| Route length 
 |- 
 !Text only !! Readable words 
 |- 
 |I-91 || 277 kB || 18 kB || 2905 words || 290 mi 
 |- 
 |I-93 || 300 kB || 21 kB || 3488 words || 190 mi 
 |- 
 |I-68 || 203 kB || 20 kB || 3300 words || 113 mi 
 |- 
 |I-8 || 402 kB || 40 kB || 6795 words || 350 mi 
 |- 
 |I-80 (IA) || 243 kB || 23 kB || 3932 words || 306 mi 
 |- 
 |I-75 (MI) || 448 kB || 33 kB || 5597 words || 396 mi 
 |- 
 |I-70 (UT) || 174 kB || 20 kB || 3488 words || 232 mi 
 |- 
 |} 
 :You'll notice that except for I-91 and I-93, these are all Featured Articles.  I added some state-detail articles to this because the highways were of comparable lengths to all of I-91.  Where am I going with this?  Instead of focusing on the length of the article, we should be focusing on the quality.  I-91 can become a FA with the right effort, but I believe splitting the article into state-detail articles for the sake of splitting them would be detrimental to the project. –