Except as otherwise provided by law, the commission at any time and from time to time may:
(a) Select, adopt, and determine the location for State highways on routes authorized by law.
(b) Allocate, from the funds available therefor, moneys for the construction, improvement or maintenance of the various highways or portions thereof under the jurisdiction of the department. The commission may determine in each case the maximum sum of money that shall be made available therefor.
(c) Authorize preliminary surveys to determine the advisability of including in or excluding from the State highway system any highway or portion thereof.