Scour-Critical Bridges in Louisiana
Louisiana has 1,302 bridges rated scour-critical by the Federal Highway Administration. These bridges have foundations that are unstable or at risk of undermining during flood events. Scour-critical doesn't mean a bridge is about to collapse — it means extra monitoring and countermeasures are in place — but these structures are priorities for repair or replacement.
How this ranking works
This state list filters to NBI scour ratings 0 through 3, then sorts by average daily traffic. It is intended to show flood-vulnerability exposure, not to label any bridge as currently unsafe.
| Bridge | County | Scour Rating | Daily Traffic | Condition |
|---|---|---|---|---|
| I0012 over West Colyell CR | Livingston | 3 — Serious | 77,469 | Fair |
| I0012 over Big Branch | Livingston | 3 — Serious | 75,867 | Fair |
| I0012 over Blood River | Livingston | 3 — Serious | 74,180 | Fair |
| I0110 over City Streets | East Baton Rouge | 3 — Serious | 64,059 | Fair |
| I0012 over Yellow Water River Rel. | Tangipahoa | 3 — Serious | 58,377 | Good |
| I0012 over Selsers Creek | Tangipahoa | 3 — Serious | 53,386 | Fair |
| Us0190 over Abita River | St. Tammany | 3 — Serious | 45,574 | Fair |
| I0012 over Big Branch | Livingston | 3 — Serious | 44,252 | Good |
| I0012 over Blood River | Livingston | 3 — Serious | 44,252 | Fair |
| I0020 over Cooley Branch | Webster | 3 — Serious | 44,225 | Fair |
| I0020 over Cooley Branch | Webster | 3 — Serious | 44,225 | Good |
| I0055 over Pass Manchac | Tangipahoa | 3 — Serious | 39,850 | Fair |
| I0055 over Ponchatoula Cr. | Tangipahoa | 3 — Serious | 39,850 | Good |
| I0020 over Dorcheat Bayou | Webster | 3 — Serious | 38,625 | Fair |
| I0020 over Crows CR Relief | Bienville | 3 — Serious | 37,514 | Fair |
| I0020 over Crows CR Relief | Bienville | 3 — Serious | 37,514 | Poor |
| I0020 over Black Lake Creek | Bienville | 2 — Critical | 37,514 | Fair |
| I0020 over Black Lake Creek | Bienville | 2 — Critical | 37,514 | Fair |
| I0012 over West Colyell CR | Livingston | 3 — Serious | 37,161 | Fair |
| I0012 over Natalbany River | Tangipahoa | 3 — Serious | 37,140 | Fair |
| I0059 over Yellow Bayou | St. Tammany | 3 — Serious | 36,841 | Fair |
| I0059 over Dry Bayou | St. Tammany | 3 — Serious | 36,841 | Fair |
| I0059 over Indian Bayou | St. Tammany | 3 — Serious | 36,841 | Fair |
| I0059 over Clear Bayou | St. Tammany | 3 — Serious | 36,841 | Fair |
| La3025 over Coulee Mine | Lafayette | 3 — Serious | 34,877 | Fair |
| La0447 over West Colyell CR | Livingston | 3 — Serious | 34,245 | Good |
| I0059 over Yellow Bayou | St. Tammany | 3 — Serious | 33,925 | Fair |
| I0059 over Middle Slough | St. Tammany | 3 — Serious | 33,925 | Fair |
| I0059 over Dry Bayou | St. Tammany | 3 — Serious | 33,925 | Fair |
| I0059 over Indian Bayou | St. Tammany | 3 — Serious | 33,925 | Fair |
| I0059 over Clear Bayou | St. Tammany | 3 — Serious | 33,925 | Fair |
| I0020 over Dorchear Bayou Rel | Webster | 3 — Serious | 32,869 | Fair |
| I0020 over Dorcheat Bayou | Webster | 3 — Serious | 32,869 | Fair |
| I0010 over Wards Creek | East Baton Rouge | 3 — Serious | 32,092 | Fair |
| I0110 over City Streets | East Baton Rouge | 3 — Serious | 32,092 | Fair |
| I0049 over Rambin Bayou | De Soto | 3 — Serious | 28,142 | Fair |
| I0049 over Jonhson Chute Bayou | Natchitoches | 3 — Serious | 28,142 | Fair |
| La0427 over Dawson Cr.brg.(acadian) | East Baton Rouge | 3 — Serious | 22,447 | Fair |
| La0001 over Mcain Creek | Caddo | 3 — Serious | 21,933 | Fair |
| I0055 over Ponchatoula Cr. | Tangipahoa | 3 — Serious | 21,736 | Good |
| Bluebonnet BLVD over Dawson Creek/bluebonnet | East Baton Rouge | 3 — Serious | 21,296 | Fair |
| Bluebonnet BLVD over Dawson Creek/bluebonnet | East Baton Rouge | 3 — Serious | 21,296 | Fair |
| Us0190 over Ponchatoula Creek C | Tangipahoa | 3 — Serious | 21,045 | Fair |
| Us0165 over Flagon Bayou Relief | Rapides | 3 — Serious | 20,902 | Good |
| I0049 over Diversion Canal | Rapides | 3 — Serious | 20,572 | Good |
| La0526 over Brush Bayou | Caddo | 3 — Serious | 19,314 | Fair |
| La0094 over Vermilion River | St. Martin | 3 — Serious | 18,293 | Fair |
| Us0080 over Ouachita River-louisvill | Ouachita | 3 — Serious | 17,683 | Fair |
| I0012 over Selsers Creek | Tangipahoa | 3 — Serious | 17,665 | Fair |
| Us0190 over Greys Creek | Livingston | 3 — Serious | 17,500 | Good |
| Us0171 over South Brush Bayou | Caddo | 3 — Serious | 16,911 | Fair |
| La3094 over Cross Bayou | Caddo | 3 — Serious | 16,911 | Poor |
| La0526 over Brush Bayou | Caddo | 3 — Serious | 16,911 | Fair |
| La0182 over Carencro Bayou | St. Landry | 3 — Serious | 16,573 | Fair |
| La0022 over Tchefuncte R/madisonvill | St. Tammany | 3 — Serious | 16,517 | Fair |
| La0173 over Cross Bayou | Caddo | 3 — Serious | 15,302 | Good |
| Us0190 over Abita River | St. Tammany | 3 — Serious | 14,668 | Good |
| I0055 over Pass Manchac | Tangipahoa | 3 — Serious | 14,300 | Fair |
| La0059 over Chinchuba Branch | St. Tammany | 3 — Serious | 14,110 | Fair |
| La0059 over Abita River | St. Tammany | 3 — Serious | 14,110 | Fair |
| La3094 over Cross Bayou | Caddo | 3 — Serious | 14,003 | Poor |
| La0022 over Selsers Creek | Tangipahoa | 3 — Serious | 12,900 | Fair |
| La0182 over Atchaf.r/berwick Bay | St. Mary | 2 — Critical | 12,788 | Poor |
| La0308 over Drainage Canal | Lafourche | 3 — Serious | 12,186 | Fair |
| La0010 over Bogue Chitto Relief | Washington | 3 — Serious | 12,018 | Good |
| La0010 over Bogue Chitto River | Washington | 3 — Serious | 12,018 | Good |
| I0049 over Diversion Canal | Rapides | 3 — Serious | 11,969 | Good |
| La0544 over Mill Creek | Lincoln | 3 — Serious | 11,636 | Fair |
| La0544 over Wafer Creek | Lincoln | 3 — Serious | 11,636 | Fair |
| La0544 over Cypress Creek | Lincoln | 3 — Serious | 11,636 | Poor |
| Us0190 over West Colyell Cr. | Livingston | 3 — Serious | 11,488 | Fair |
| La0427 over Bayou Manchac | Ascension | 3 — Serious | 11,384 | Poor |
| La0019 over White Bayou | East Baton Rouge | 2 — Critical | 11,198 | Poor |
| Clyde Fant PKWY over Cross Bayou | Caddo | 3 — Serious | 11,190 | Fair |
| Us0167 over Bayou Joe Morcel | Evangeline | 3 — Serious | 11,126 | Good |
| La3036 over Cross Bayou | Caddo | 3 — Serious | 10,312 | Fair |
| Us0190 over Amite River | Livingston | 3 — Serious | 10,200 | Good |
| La0016 over Willis Bayou | Livingston | 3 — Serious | 10,070 | Fair |
| Us0090 over Wax Lake Outlet | St. Mary | 2 — Critical | 10,035 | Poor |
| Us0079 over Crows Creek | Claiborne | 3 — Serious | 9,942 | Fair |
| Us0190 over Big Branch | St. Tammany | 2 — Critical | 9,941 | Fair |
| Us0190 over Mid Colyell Cr. | Livingston | 3 — Serious | 9,745 | Fair |
| La0431 over Black Bayou | Ascension | 3 — Serious | 9,608 | Poor |
| La0431 over Lake Villar | Ascension | 3 — Serious | 9,608 | Fair |
| Us0190 over Bogue Falaya | St. Tammany | 3 — Serious | 9,408 | Fair |
| La1032 over Grays Creek | Livingston | 3 — Serious | 9,267 | Fair |
| Us0080 over Bayou Dorcheat | Webster | 3 — Serious | 9,109 | Poor |
| La0037 over Hubs Bayou | East Baton Rouge | 3 — Serious | 9,104 | Poor |
| Us0190 over Drain | Tangipahoa | 3 — Serious | 9,053 | Fair |
| Us0190 over Lit Natalbany R. | Livingston | 2 — Critical | 8,928 | Good |
| La0034 over Cheniere Creek | Ouachita | 3 — Serious | 8,694 | Poor |
| La0612 over Flat River | Bossier | 3 — Serious | 8,332 | Fair |
| La3280 over Ouachita River | Ouachita | 3 — Serious | 8,312 | Fair |
| Us0190 over Branch | Tangipahoa | 3 — Serious | 8,262 | Fair |
| Us0190 over Holden Branch | Tangipahoa | 3 — Serious | 8,262 | Fair |
| Us0190 over Creek | Tangipahoa | 3 — Serious | 8,262 | Fair |
| La0021 over Bogue Chitto Rv. Relief | St. Tammany | 3 — Serious | 8,257 | Good |
| La0021 over Bogue Chitto River | St. Tammany | 3 — Serious | 8,257 | Good |
| Gloria Switch RD over Vermilion River | Lafayette | 3 — Serious | 8,240 | Fair |
| Canal BLVD over Lafourche Bayou | Lafourche | 3 — Serious | 8,110 | Fair |
| La0838 over Cheniere Creek | Ouachita | 3 — Serious | 8,105 | Fair |
| La0838 over Creek | Ouachita | 3 — Serious | 8,105 | Fair |
| La0838 over Steep Bayou | Ouachita | 3 — Serious | 8,105 | Poor |
| Us0190 over Ponchatoula Cr. | Tangipahoa | 3 — Serious | 7,716 | Fair |
| La3036 over Cross Bayou | Caddo | 3 — Serious | 7,587 | Fair |
| Flournoy Lucas RD over Brushy Bayou | Caddo | 3 — Serious | 7,518 | Fair |
| La0021 over Bogue Chitto Rv Relief | St. Tammany | 3 — Serious | 7,481 | Good |
| La0021 over Bogue Chitto River | St. Tammany | 3 — Serious | 7,481 | Good |
| Us0190 over Coyell Creek | Livingston | 3 — Serious | 7,215 | Fair |
| La1025 over West Colyell CR | Livingston | 3 — Serious | 7,211 | Fair |
| La1040 over Yellow Water River | Tangipahoa | 3 — Serious | 7,190 | Poor |
| Us0190 over Hog Branch | Livingston | 3 — Serious | 7,126 | Fair |
| Us0190 over Tickfaw River | Livingston | 3 — Serious | 7,126 | Fair |
| Us0165 over Old Slough | Grant | 3 — Serious | 7,084 | Fair |
| Us0165 over Big Creek | Grant | 3 — Serious | 7,084 | Fair |
| Us0165 over Fish Creek | Grant | 3 — Serious | 7,084 | Fair |
| Us0171 over Rambin Bayou | De Soto | 3 — Serious | 6,956 | Fair |
| Us0171 over Rambin Bayou | De Soto | 3 — Serious | 6,604 | Fair |
| Us0165 over Big Creek | Grant | 3 — Serious | 6,586 | Fair |
| La1027 over West Colyell CR | Livingston | 3 — Serious | 6,554 | Fair |
| La0443 over Skulls Creek | Tangipahoa | 3 — Serious | 6,478 | Poor |
| La0443 over Tang River Relief | Tangipahoa | 3 — Serious | 6,478 | Fair |
| La0443 over Tangipahoa River Relief | Tangipahoa | 3 — Serious | 6,478 | Good |
| La0022 over Drain | Tangipahoa | 3 — Serious | 6,435 | Fair |
| La0022 over Drain | Tangipahoa | 3 — Serious | 6,435 | Fair |
| La0022 over Tangipahoa River | Tangipahoa | 3 — Serious | 6,435 | Poor |
| La0546 over Cheniere Creek | Ouachita | 3 — Serious | 6,382 | Fair |
| Us0084 over Bayou Castor | De Soto | 3 — Serious | 6,314 | Poor |
| South Range Road over Ponchatoula Creek | Tangipahoa | 3 — Serious | 6,250 | Fair |
| Broadway Avenue over Chatlin Lake Canal | Rapides | 3 — Serious | 6,200 | Good |
| La0933 over Roddy Bayou | Ascension | 3 — Serious | 6,131 | Good |
| La1085 over Fox Branch | St. Tammany | 3 — Serious | 6,010 | Fair |
| Southern Loop over Trib To Boggy Bayou | Caddo | 3 — Serious | 6,000 | Good |
| La0067 over Comite River | East Feliciana | 3 — Serious | 5,772 | Fair |
| La0145 over Squires Creek | Lincoln | 3 — Serious | 5,661 | Fair |
| Us0171 over Bear Creek | De Soto | 3 — Serious | 5,659 | Fair |
| Harvey BLVD over Outfall Canal | Jefferson | 3 — Serious | 5,650 | Good |
| Harvey BLVD over Fallout Canal | Jefferson | 3 — Serious | 5,650 | Good |
| Wardline Road over Yellow Water River | Tangipahoa | 3 — Serious | 5,582 | Fair |
| La0021 over Drain | Washington | 3 — Serious | 5,485 | Fair |
| La0021 over Pushapatapa CR | Washington | 3 — Serious | 5,485 | Good |
| La0157 over Fox Skin Bayou | Bossier | 3 — Serious | 5,436 | Poor |
| La0934 over Black Bayou | Ascension | 3 — Serious | 5,367 | Poor |
| Us0084 over Bayou | De Soto | 3 — Serious | 5,350 | Fair |
| Us0084 over Clifton Bayou | De Soto | 3 — Serious | 5,350 | Fair |
| La0013 over Bayou Des Cannes | Evangeline | 3 — Serious | 5,328 | Fair |
| La0006 over Winn Creek | Natchitoches | 3 — Serious | 5,328 | Fair |
| Us0171 over Bear Creek | Sabine | 3 — Serious | 5,228 | Fair |
| La3124 over Bogue Lusa Creek | Washington | 2 — Critical | 5,213 | Fair |
| Us0171 over Bayou San Miguel | Sabine | 3 — Serious | 5,192 | Good |
| La0040 over Bills Branch | St. Tammany | 3 — Serious | 5,160 | Fair |
| La0040 over Simalousa Creek | St. Tammany | 3 — Serious | 5,160 | Fair |
| Springridge-texas over Mill Creek | Caddo | 3 — Serious | 5,102 | Good |
| Springridge-texas over Mill Creek | Caddo | 3 — Serious | 5,102 | Fair |
| Us0084 over Fourmile Bayou | De Soto | 3 — Serious | 5,051 | Fair |
| La0442 over L Natalbany River | Livingston | 3 — Serious | 5,026 | Fair |
| La0442 over Nat. River Relief | Tangipahoa | 3 — Serious | 5,026 | Fair |
| La0442 over Natalbany River | Tangipahoa | 3 — Serious | 5,026 | Fair |
| La0442 over Ponchatoula Creek | Tangipahoa | 3 — Serious | 5,026 | Fair |
| La0033 over Mill Creek | Union | 3 — Serious | 5,013 | Fair |
| La0016 over Coon Branch | Tangipahoa | 3 — Serious | 4,942 | Fair |
| La0830-6 over Horse Bayou | Morehouse | 3 — Serious | 4,905 | Poor |
| La7822 over Macks Bayou | Bossier | 3 — Serious | 4,896 | Fair |
| Us0171 over Middle Relief | Sabine | 3 — Serious | 4,790 | Fair |
| Us0171 over Bayou San Miguel | Sabine | 3 — Serious | 4,790 | Fair |
| Us0171 over Bayou San Patricio | Sabine | 3 — Serious | 4,790 | Good |
| La0040 over Drain | Tangipahoa | 3 — Serious | 4,748 | Good |
| La0040 over Tangipahoa River | Tangipahoa | 3 — Serious | 4,748 | Fair |
| La0040 over Davis Branch | Tangipahoa | 3 — Serious | 4,748 | Good |
| La0040 over Sweetwater Creek | Tangipahoa | 3 — Serious | 4,748 | Fair |
| Frenchtown RD over Draughan Creek | East Baton Rouge | 3 — Serious | 4,745 | Poor |
| La0021 over Creek | Washington | 3 — Serious | 4,719 | Fair |
| La0430 over Drain | Washington | 3 — Serious | 4,643 | Fair |
| La0059 over Long Branch Bayou | St. Tammany | 3 — Serious | 4,612 | Poor |
| La0059 over Long Branch Bayou | St. Tammany | 3 — Serious | 4,612 | Fair |
| La0162 over Black Bayou | Bossier | 3 — Serious | 4,595 | Poor |
| La0162 over Little Caney Bayou | Bossier | 3 — Serious | 4,595 | Fair |
| Us0165 over Little River Relief | La Salle | 3 — Serious | 4,538 | Fair |
| Us0165 over Little River | La Salle | 3 — Serious | 4,538 | Good |
| Us0165 over Cockerham Creek | La Salle | 3 — Serious | 4,538 | Good |
| La1026 over Canal | Livingston | 3 — Serious | 4,534 | Fair |
| La3265 over Bayou Clear | Rapides | 3 — Serious | 4,368 | Fair |
| Us0084 over Dugdemona River Relief | Winn | 3 — Serious | 4,317 | Good |
| La0525 over Creek | Caddo | 3 — Serious | 4,294 | Fair |
| La0525 over Buchanan Bayou | Caddo | 3 — Serious | 4,294 | Fair |
| La0525 over Boggy Bayou | Caddo | 3 — Serious | 4,294 | Fair |
| La0525 over Boggy Bayou | Caddo | 3 — Serious | 4,294 | Poor |
| Us0084 over Drain | De Soto | 3 — Serious | 4,251 | Fair |
| Us0084 over Bayou Grand Cane | De Soto | 3 — Serious | 4,251 | Fair |
| Us0084 over B.grand Cane Rlf | De Soto | 3 — Serious | 4,251 | Fair |
| Susek DR over Maria Bayou Trib. #3 | Rapides | 3 — Serious | 4,200 | Good |
| Susek DR over Bayou Maria | Rapides | 3 — Serious | 4,200 | Good |
| La0435 over Abita River | St. Tammany | 3 — Serious | 4,200 | Fair |
| Blount RD over Creek | East Baton Rouge | 3 — Serious | 4,167 | Good |
| La0100 over Bayou Plaquemine Brule | Acadia | 3 — Serious | 4,120 | Fair |
| Old US 51 over Pass Manchac | Tangipahoa | 2 — Critical | 4,107 | Poor |
| Bowie RD over Coulee | Lafourche | 3 — Serious | 4,080 | Fair |
| La0042 over Tickfaw River | Livingston | 3 — Serious | 4,071 | Fair |
| La0175 over Caney Bayou Rel | De Soto | 3 — Serious | 4,051 | Poor |
| Sligo RD over Hogskin Lake Creek | Bossier | 3 — Serious | 4,000 | Fair |