The comparative meaning in this phrase is only implied.
There are merely 2 parts in this phrase:
快 - Fast.
一点儿 - A little.
So there is no comparative element. Nonetheless these 2 are sufficient to imply a comparative meaning.
儿 is an optional voice change and can be omitted.
一 also can be omitted. So 一点儿 can be reduced to
点儿, 一点 or just 点 without changing the meaning.
I have a date at night. I want to finish the work faster. (this is a literal translation)
The comparative and superlative structure in Chinese are simple: using the preposition 比 and the adverb 最 respectively.
In a simple predicative sentence,.
A 比 B [Adj.] → A is more [Adj.] than B.
A 最 [Adj.] → A is the most [Adj.]
他比你高。/He is taller than you.
他最高。/He is the tallest.
To apply in an adverbial phrase, insert the structure after the structural particle 得.
He runs faster than you.
He runs the fastest.