THE DIRECTOR OF BOSTON'S "BIG DIG" HIGHWAY TUNNEL PROGRAM AGREED ON THURSDAY TO RESIGN, TWO WEEKS AFTER A TUNNEL CEILING COLLAPSED AND KILLED A MOTORIST, REUTERS REPORTED. MATTHEW AMORELLO STEPPED DOWN AS CHAIRMAN AND CHIEF EXECUTIVE OFFICER OF THE MASSACHUSETTS TURNPIKE AUTHORITY, HOURS BEFORE A HEARING CALLED BY THE STATE'S GOVERNOR TO OUST HIM WAS SET TO BEGIN. AMORELLO CAME UNDER FIRE AFTER A 3-TON PORTION OF THE TUNNEL CEILING COLLAPSED ON JULY 10, KILLING A WOMAN IN A CAR. PARTS OF THE 7.8-MILE (12.6 KM) TUNNEL SYSTEM HAVE BEEN CLOSED FOR SAFETY CHECKS SINCE THE ACCIDENT, CAUSING MAJOR TRAFFIC JAMS. SAFETY CONCERNS OVER THE METHOD FOR HOLDING UP THE CONCRETE PANELS -- IN WHICH BOLTS WERE INSERTED INTO EPOXY-FILLED HOLES DRILLED INTO THE CEILING -- WERE FIRST RAISED IN 1999, ACCORDING TO LOCAL NEWSPAPERS. MASSACHUSETTS GOV. MITT ROMNEY, A 2008 REPUBLICAN PRESIDENTIAL HOPEFUL, HAS BEEN CALLING FOR AMORELLO'S RESIGNATION SINCE THE DAY AFTER THE COLLAPSE. "THAT TRAGIC EVENT MADE IT ABUNDANTLY CLEAR THAT BUSINESS AS USUAL AT THE TURNPIKE AUTHORITY HAD TO CHANGE AND THAT NEW LEADERSHIP HAD TO BE BROUGHT IN TO RESTORE PUBLIC CONFIDENCE," ROMNEY SAID ON THURSDAY. ROMNEY SAID HE HAD NOT YET DECIDED WHO HE WOULD NAME TO SUCCEED AMORELLO, WHOSE RESIGNATION IS EFFECTIVE AUG. 15. HE SAID HE MIGHT SEPARATE THE CHAIRMAN AND CEO POSTS, POSSIBLY GIVING THE CHAIRMANSHIP TO MASSACHUSETTS TRANSPORTATION SECRETARY JOHN COGLIANO AND NAMING AN EXECUTIVE DIRECTOR WITH CONSTRUCTION AND ENGINEERING EXPERIENCE. "I WANT SOMEBODY WHO KNOWS HOW THE WHEELS OF AUTOMOBILES AND TRUCKS TURN AND HOW ENGINEERS CAN DO A FINE JOB FINISHING THE WORK OF THE BIG DIG," ROMNEY SAID. AMORELLO, WHO WAS APPOINTED TO HIS POST IN 2002, SAID HE STEPPED DOWN AFTER REALIZING THAT LOSING HIS JOB WAS INEVITABLE. "I SAID TO ALL OF YOU THAT I WOULD NOT RESIGN BECAUSE I DIDN'T THINK IT WOULD FIX ANYTHING OR MAGICALLY MAKE ALL THE ISSUES ASSOCIATED WITH THE BIG DIG GO AWAY," AMORELLO TOLD REPORTERS. "I STILL DON'T BELIEVE IT WILL, BUT TO GO INTO A HEARING WITH A FOREGONE CONCLUSION MAKES NO SENSE FOR ME." CHALLENGES REMAIN AMORELLO'S RESIGNATION GIVES ROMNEY A CHANCE TO PUT SOMEONE NEW IN CHARGE OF THE $15 BILLION "BIG DIG," THE COUNTRY'S MOST EXPENSIVE PUBLIC WORKS PROJECT, WHICH HAS BEEN PLAGUED BY COST OVERRUNS, FAULTY CONSTRUCTION AND LEAKS. IF THAT PERSON SOLVES THE TUNNEL'S ENGINEERING PROBLEMS, IT COULD GIVE ROMNEY A BOOST IN HIS QUEST FOR THE REPUBLICAN PRESIDENTIAL NOMINATION, OBSERVERS SAID. BUT THAT'S NOT A GUARANTEED OUTCOME. "THIS IS OBVIOUSLY NOT A QUICK FIX," SAID JULIAN ZELIZER, A HISTORY PROFESSOR AT BOSTON UNIVERSITY. "THERE ARE HUGE STRUCTURAL PROBLEMS WITH THE BIG DIG." STATE OFFICIALS HAVE NOT YET OFFERED A FIRM TIMETABLE FOR WHEN THE FULL TUNNEL SYSTEM WILL REOPEN. "THE PROBLEM FOR GOV. ROMNEY NOW IS THAT HE NEVER ARTICULATED WHAT HE WANTED DIFFERENT AT THE MASSACHUSETTS TURNPIKE AUTHORITY OTHER THAN THAT HE WANTED NEW LEADERSHIP," SAID JEFFREY BERRY, PROFESSOR OF POLITICAL SCIENCE AT TUFTS UNIVERSITY. "THE FURTHER WE GET AWAY FROM AMORELLO, THE MORE THE QUESTION WILL EMERGE OF 'WHAT'S YOUR POSITION AND WHAT DO YOU WANT TO DO DIFFERENTLY?"