Howard County Highway Maintenance 4301 State Route 32 Dayton, MD 21036 Phone : (410) 313-7450 Business Category Government Offices-County Legislative Bodies Howard County--public Works Department Of, Bureau Of Highways Ellicott City, MD 21043 Phone : (410) 313-7450 Business Category Government Offices-County Government Offices & Public Schools Howard County--highway Maintenance Ellicott City, MD 21043 Phone : (410) 313-7450 Business Category Government Offices-County Government Offices & Public Schools