Nowadays I only see it written as 交差点, but some years ago, I clearly remember seeing it as 交叉点 .
Wiktionary says the old spelling was 交叉點, the 點 is the 旧字体 of 点、which makes sense.
But when did the 叉>差 代用字 thing occured?
I suspect it was around mid 1990ies. There seem to have interesting pages on yahoo Japan, but they are blocked from browsing from outside of Japan…
Do some one of you have some info ?
Thanks
I’ve never come across that for Yahoo pages - maybe they’re just blocked inside of wherever you are. 
For example, this page says it occured with the release of 法令用語改正要領 in 昭和56 = 1981.
I think they block it for accesses from Europe. For pages you care about you can feed the URL into the internet archive’s search page – the archiver is in the US and can see the real page and fetch it for you.
This discussion led me to a different rabbit hole. The Japanese definition for 交差点 in my dictionary app mentions 丁字路 (T junction) which I thought was cute because of the use of the kanji 丁 for its shape.
What surprised me is that it’s read ていじろ. I wondered if the てい came from Latin T but apparently it’s coincidental and it’s just a 漢音 reading of the kanji (which I just realized I should have remembered because of 丁寧).
At least it’s easy to remember!
The reading section this week for the IBC book club book せーラー服と機関銃 coincidentally has a usage of 交叉点 (page 318; printed with furigana). The book was originally written in 1981, this is the revised edition of 2006. Akagawa’s style does not generally make a lot of use of odd kanji choices, so it’s interesting that he did so here.