What is a ‘barrier-free’ vehicle?

One of my colleagues asked this question, which is ”What is a ‘barrier-free’ vehicle?”

Here's my answer and I hope I should be correct.

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This "barrier-free" means "no blockers or no obstacles”, especially in using vehicles in this case.

Recently in Japan, the percentage of senior persons occupied in population has been getting bigger and bigger.
Every manufacturer of any vehicles takes account of this fact.
Seniors can be dominant customers to those vehicle manufactures in very near future.

So eliminating any obstacles for a senior to use a car must be essential.

For example, any gauge in front of you must have larger letters.
The sensors to sense a wall, car, children playing behind the car when you drive backward might be help for seniors.

"barrier-free" is a Japanese coined word, I guess.