U.S. 51 travels 69 miles northward from its beginning in Laplace to Hammond, Independence, Amite, Tangipahoa and Kentwood in southeastern Louisiana. The route shares an alignment with Interstate 55 north from outside Laplace to a bypass west of Ponchatoula, and parallels the freeway to the east from Hammond to the Mississippi state line.
Bridges carrying Interstate 55 /U.S. 51 and Old U.S. 51 span Pass Manchac, a channel linking Lake Maurepas with Lake Pontchartrain. Photo taken May 9, 2015.
Until 1951, U.S. 51 joined U.S. 61 and 65 from Laplace southeast into New Orleans. The overlaps of both U.S. 51 and 65 along U.S. 61 were established to guide through travelers northward to Mississippi.
The 8.6-mile business route for U.S. 51 follows the pre-1965 alignment of the US highway through both Ponchatoula and Hammond. U.S. 51 Business separates from I-55/U.S. 51 at Exit 23 and runs northward along Railroad Avenue to Pine Street (LA 22) west in Downtown Ponchatoula. LA 22/U.S. 51 Business overlap west to Veterans Avenue, which extends the business route north from Ponchatoula to Hammond and Interstate 12 at Exit 40. Through Hammond, U.S. 51 Business follows SW Railroad Avenue to Downtown, where it joins U.S. 190 along a one-way street couplet (Thomas Street west / Morris Avenue). U.S. 51 Business and U.S. 190 overlap 1.25 miles west to the commercialized intersection with U.S. 51 (Morrison Boulevard).
||U.S. 51 shield posted at the intersection of Oak Street and U.S. 190 (Morris Avenue) east in Downtown Hammond. U.S. 51 Business is routinely signed as the U.S. 51 mainline in Hammond. Photo taken 11/20/08. |
||U.S. 51 Business (Oak Street) south at Coleman Avenue and Zemurray Park. Photo taken 11/20/08. |
||U.S. 51 Business curves southeast from Oak Street to join Railroad Avenue ahead of 1st Avenue. Photo taken 11/20/08. |
||Following Railroad Avenue, a five-lane arterial, U.S. 51 Business approaches a traffic light at Old Covington Highway. Old Covington Highway east from Hammond was once a part of LA 1067. Photo taken 11/20/08. |
||A myriad of traveler services line U.S. 51 Business (Railroad Avenue) ahead of a diamond interchange with Interstate 12. Photo taken 11/20/08. |
||Adjacent Hammond Square Mall adds to the traffic congestion along U.S. 51 Business (Railroad Avenue) south at Interstate 12. Photo taken 11/20/08. |
Page Updated 10-04-2016.