It is only totaled if the repair cost exceeds the car value. Any damage to the frame can get very expensive to repair.
My kid had an accident with front end damage a few years ago on our 06 TSX. The air bag replacement, A/C condenser, and HIDs were the big ticket items (no frame damage). The USAA rep put the cost of repairs barely above the book value of my 06 TSX. I had a lot of extras on this TSX (Aspec suspension, aftermarket rims, aspec body kit, progress rsb, new brakes, remote start, brand new tires, etc...) and I didn't want to lose the additional $$$ value to me.
I worked out a deal to put the repair cost below the totaled out value and I would pay the rest out of pocket. I just had to pay my deductible and about $600 out of pocket to get the TSX repaired. My kid spent the next 2 years doing extra chores to work off the $600. It still cost me more in the long run because our insurance rates went up and I had to drop down to liability for the TSX. That was in Mar/2014 and the TSX has been running perfectly since (the kid still drives it in college and REALLY takes care of it).
Son - 06 TSX 5AT w/ Navi, Carbon Gray w/ Quartz (handed down for 16th B-day Mar/14)
His - 08 RDX Tech, Moroccan Red Pearl w/ Taupe (finally replaced Takata airbag on 6/16/16 after 86 days with rental)
Her - 11 MDX Adv/Ent, Palladium Metallic w/ Ebony