diff --git a/flake.lock b/flake.lock
index f133326..12941fe 100644
--- a/flake.lock
+++ b/flake.lock
@@ -622,6 +622,23 @@
         "type": "github"
       }
     },
+    "osrm-backend": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1731259907,
+        "narHash": "sha256-WD7QvwGaJZRaFCdlrPxMWU6zhkZJIQ7veWdkJrzm65E=",
+        "owner": "nammayatri",
+        "repo": "osrm-backend",
+        "rev": "07851a158536a477082aa546c69d7e1928b7a284",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nammayatri",
+        "ref": "Backend/feat/adding-one-to-one-distance-calculation",
+        "repo": "osrm-backend",
+        "type": "github"
+      }
+    },
     "pre-commit-hooks": {
       "inputs": {
         "flake-compat": [
@@ -724,6 +741,7 @@
           "common",
           "nixpkgs"
         ],
+        "osrm-backend": "osrm-backend",
         "systems": [
           "common",
           "systems"
diff --git a/flake.nix b/flake.nix
index c0d91e9..95a93ef 100644
--- a/flake.nix
+++ b/flake.nix
@@ -8,17 +8,22 @@
     # data files
     india-latest.url = "https://download.geofabrik.de/asia/india-latest.osm.pbf";
     india-latest.flake = false;
+
+    osrm-backend = {
+      url = "github:nammayatri/osrm-backend/Backend/feat/adding-one-to-one-distance-calculation";
+      flake = false;
+    };
   };
 
   outputs = inputs:
     inputs.flake-parts.lib.mkFlake { inherit inputs; } {
       systems = import inputs.systems;
       imports = [
-        ./osrm.nix
+        (import ./osrm.nix { osrmBackend = inputs.osrm-backend; inherit inputs; })
         ./docker.nix
       ];
       perSystem = { self', pkgs, lib, ... }: {
         formatter = pkgs.nixpkgs-fmt;
       };
     };
-}
+}
\ No newline at end of file
diff --git a/osrm.nix b/osrm.nix
index c302c65..1f6914d 100644
--- a/osrm.nix
+++ b/osrm.nix
@@ -1,4 +1,4 @@
-{ inputs, ... }:
+{ osrmBackend, inputs, ... }:
 
 let
   openStreetDataFileName = "india-latest";
@@ -11,31 +11,68 @@ in
     packages =
       rec {
         # Patch osrm-backend to use our own car.lua file
-        osrm-backend = pkgs.osrm-backend.overrideAttrs (oa: {
-          # TODO: Use `patches` to directly patch the car.lua file.
-          # Or, use a fork of osrm-backend, and point to it.
-          src = pkgs.runCommandNoCC "osrm-backend-patched-src" { } ''
-            cp -r ${oa.src} $out
-            chmod -R u+w $out
+        patched-osrm-backend = pkgs.stdenv.mkDerivation {
+          name = "patched-osrm-backend";
+          src = osrmBackend;
+          buildInputs = [
+            pkgs.cmake
+            pkgs.boost
+            pkgs.tbb_2021_8 # Use TBB 2021.8 explicitly
+            pkgs.expat
+            pkgs.bzip2
+            pkgs.libzip
+            pkgs.pkg-config
+            pkgs.lua5_2 # Updated to Lua 5.3
+          ];
+
+          phases = [ "unpackPhase" "buildPhase" "installPhase" ];
+          buildPhase = ''
+            mkdir build
+            cd build
+            cmake .. \
+              -DENABLE_MASON=ON \
+              -DTBB_ROOT=${pkgs.tbb_2021_8} \
+              -DCMAKE_PREFIX_PATH="${pkgs.boost};${pkgs.tbb_2021_8};${pkgs.expat};${pkgs.bzip2};${pkgs.lua5_3}" \
+              -DCMAKE_CXX_STANDARD=20 \
+              -DCMAKE_CXX_FLAGS="-std=c++20 -stdlib=libc++" \
+              -DCMAKE_INSTALL_PREFIX=$out
+            make
+          '';
+          installPhase = ''
+            mkdir -p $out/bin $out/profiles
+            cp build/osrm-* $out/bin/
             cp ${carLuaPath} $out/profiles/car.lua
           '';
-        });
-
-        osrm-data =
-          pkgs.runCommandNoCC "osrm-data"
-            { buildInputs = [ self'.packages.osrm-backend ]; }
-            ''
-              mkdir $out && cd $out
-              ln -s ${inputs.india-latest} ${openStreetDataFileName}.osm.pbf
-              ln -s ${speedDataPath} ${indiaSpeedDataFileName}.csv
-              osrm-extract -p ${self'.packages.osrm-backend}/share/osrm/profiles/car.lua ${openStreetDataFileName}.osm.pbf
-              osrm-partition ${openStreetDataFileName}.osrm
-              osrm-customize --segment-speed-file ${indiaSpeedDataFileName}.csv ${openStreetDataFileName}.osrm
-            '';
+        };
+
+        osrm-data = pkgs.runCommandNoCC "osrm-data"
+          { buildInputs = [ patched-osrm-backend ]; }
+          ''
+            mkdir -p $out && cd $out
+
+            # Link input files
+            ln -s ${inputs.india-latest} ${openStreetDataFileName}.osm.pbf
+            ln -s ${speedDataPath} ${indiaSpeedDataFileName}.csv
+
+            # Run OSRM tools
+            ${patched-osrm-backend}/bin/osrm-extract \
+              -p ${patched-osrm-backend}/profiles/car.lua \
+              ${openStreetDataFileName}.osm.pbf
+
+            ${patched-osrm-backend}/bin/osrm-partition \
+              ${openStreetDataFileName}.osrm
+
+            ${patched-osrm-backend}/bin/osrm-customize \
+              --segment-speed-file ${indiaSpeedDataFileName}.csv \
+              ${openStreetDataFileName}.osrm
+
+            # Move processed data to output directory
+            cp ${openStreetDataFileName}.* $out/
+          '';
 
         osrm-server = pkgs.writeShellApplication {
           name = "osrm-server";
-          runtimeInputs = [ self'.packages.osrm-backend ];
+          runtimeInputs = [ patched-osrm-backend ];
           text = ''
             set -x
             osrm-routed --algorithm mld \