Fernando made the promise yesterday amid questions surrounding his appointment since he also holds the top post at the Metropolitan Manila Development Authority (MMDA).
His critics have called his status "unconstitutional" and demanded that he immediately step down.
Fernando said he is confident that he would be able to handle both positions given his background as an engineer and mayor.
As secretary of the Department of Public Works and Highways (DPWH), he said that only dual compensation is prohibited under the law so he would not be affected because he would only be paid for his job as MMDA chairman.
"If I can not handle the job at DPWH, I would step down and quit," Fernando said.
However, he clarified that his status right now is still very uncertain because his appointment is only in an acting capacity.
He said there was a strong possibility that in the end, he would eventually be retained at only one post, depending on President Arroyo’s decision.
"I consider myself on probation at DPWH," Fernando said.
He pointed out, however, that his appointment to DPWH would help facilitate the programs of the administration to decongest Metro Manila through the recovery of sidewalks and development of more roads and transports systems for the public.
He expressed his confidence that the number of sidewalk vendors in Metro Manila would be reduced significantly in the last 18 months of the administration.
Fernando pointed out that Metro Manila represents 35 percent of the problems being faced by DPWH so his thrust would continue to be in that area.
However, he assured the public that the same programs would be implemented all over the country and that easier access between Metro Manila and the provinces would be developed in order to improve the economy.
In Metro Manila, the partial implementation of an intermodal system would take place after four months along EDSA.
Government properties located along the northbound lane of EDSA from East Avenue to North Avenue are already being developed to serve as a huge provincial bus station.
The choice of the site was based on the accessibility of the commuters by bus or MRT.
Another station would be developed in the southern portion of EDSA, specifically at Magallanes, Makati City to handle the southbound provincial buses.
In another development, the MMDA chief urged Metro Manila residents to discharge their civic duties properly, including payment of correct taxes, charges and fees to fund essential public services.
Beginning January 2003, Fernando advised residents to pay the correct individual community taxes as required by Republic Act 7160, otherwise known as the 1991 Local Government Code.
This law requires resident individuals over 18 years of age, engaged in business or occupation, or who own real property or one required to file an income tax return to pay an annual tax of P5 plus an additional P1 for every P1,000 of income regardless of whether from business, exercise of profession or from property, but not to exceed P5,000.
Every corporation doing business in the Philippines, whether domestic or resident foreign, is also liable to pay an annual community tax of P500 plus an annual additional tax, not to exceed P10,000, as follows: P2 for every P5,000 worth of real property owned by it during the preceding year based on real property tax valuation; and P2 for every P5,000 gross receipts or income, including all dividends received, derived from its business operations during the preceding year.
An MMDA staff study disclosed that many professionals, including some doctors and lawyers, paid no more than P30 as individual community tax to Metro Manila local treasurers. Similarly, not a few corporations understated their tax base, too. MMDA will try to correct this erroneous practice.