grammaticality - Is "as likely to exceed the proposed speed limit as they are the current one" correct grammar?

Please consider the question below from the GMAT verbal part. I do understand why the phrase "as ... as" is correct. Yet the use of "they are" at the very end seems odd to me.

3. Book Question: 702

Traffic safety officials predict that drivers will be equally likely to exceed the proposed speed limit as the current one.

A. equally likely to exceed the proposed speed limit as

B. equally likely to exceed the proposed speed limit as they are

C. equally likely that they will exceed the proposed speed limit as

D. as likely that they will exceed the proposed speed limit as

E. as likely to exceed the proposed speed limit as they are

Explanation

B This also offers a nonidiomatic form of comparison.

C The comparison is expressed nonidiomatically. Also, the drivers will be equally likely should be followed by to exceed rather than by that they will exceed. The resulting sentence is wordy and structurally flawed.

D The resulting sentence is wordy and structurally flawed. The idiomatic phrase as x as y is somewhat in use, but as likely that they is awkward, and the comparison is unclear and not parallel.

E Correct. The idiomatic phrase as x as y is properly used, and the comparison is clear and parallel.

Is "Traffic safety officials predict that drivers will be as likely to exceed the proposed speed limit as they are the current one" really grammatical?