diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0c4b19c027..0d141358bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -66,6 +66,7 @@
    * CHANGED: date_time refactor as a preparation to return DST/timezone related offset in the response [#4365](https://github.com/valhalla/valhalla/pull/4365)
    * ADDED: find connection on backward search for bidir matrix algo [#4329](https://github.com/valhalla/valhalla/pull/4329)
    * FIXED: Fix segfault in OSRM serializer with bannerInstructions when destination is on roundabout [#4480](https://github.com/valhalla/valhalla/pull/4481)
+   * CHANGED: Adujustment of walk speed when walking on slight downhill [#4302](https://github.com/valhalla/valhalla/pull/4302)
 
 ## Release Date: 2023-05-11 Valhalla 3.4.0
 * **Removed**
diff --git a/src/sif/pedestriancost.cc b/src/sif/pedestriancost.cc
index 1892a85f62..9ff6d35c5e 100644
--- a/src/sif/pedestriancost.cc
+++ b/src/sif/pedestriancost.cc
@@ -186,14 +186,24 @@ const BaseCostingOptionsConfig kBaseCostOptsConfig = GetBaseCostOptsConfig();
 // instead up the values of ascent/descent, e.g. 400/800 better matches
 // intermediate hikers. This will bring the uphill values quite close to the
 // ones from the exponential while still keeping downhill speed below flat speed.
+//
+// For negative angles (downhill), as per DIN 33466, speed decreases rapidly
+// as the slope becomes steeper. This behavior may hold true for mountain hikers
+// due to unpaved paths. However, it contradicts common sense for city walkers
+// when the speed factor drops below 1.0 (the walking speed on flat terrain)
+// even on a slight downhill slope. To address this, we employ a modified Tobler's
+// function to correct the factor for negative angles. Consequently, walk speed
+// slightly increases (faster than on flat terrain) when the angle is between
+// 0% and -5%, and then decreases as indicated by DIN 33466.
+// see https://gist.github.com/xlqian/0b25c8db6f45fb2c8bf68494e1ea54f1
 
 constexpr float kGradeBasedSpeedFactor[] = {
-    1.40f, // -10.0% - 0.67
-    1.32f, //  -8.0% - 0.73
-    1.26f, //  -6.5% - 0.77
-    1.20f, //  -5.0% - 0.82
-    1.12f, //  -3.0% - 0.89
-    1.06f, //  -1.5% - 0.94
+    1.33f, // -10.0% - 0.67
+    1.22f, //  -8.0% - 0.73
+    1.08f, //  -6.5% - 0.77
+    0.97f, //  -5.0% - 0.82
+    0.88f, //  -3.0% - 0.89
+    0.92f, //  -1.5% - 0.94
     1.00f, //   0.0% - 1.00
     1.10f, //   1.5% - 1.06
     1.20f, //   3.0% - 1.13