Section 8. For the performance of the department's duties relative to common carriers the commission may expend annually such sums to procure opinions, advice, plans, surveys, appraisals, audits, examinations, statistics, information, apparatus, instruments, books, tables, maps, drawings, supplies, sundries, and for travel within or without the commonwealth and expense incidental thereto, as it may from time to time deem requisite in the performance of its duties. It may from time to time cause to be made a compilation with annotations of the statutes of this commonwealth relating to common carriers.