diff --git a/src/Airports/GenAirports/runway.cxx b/src/Airports/GenAirports/runway.cxx
index 99556f2f..1b028659 100644
--- a/src/Airports/GenAirports/runway.cxx
+++ b/src/Airports/GenAirports/runway.cxx
@@ -12,6 +12,7 @@
 #include "beznode.hxx"
 #include "runway.hxx"
 
+
 extern int nudge;
 
 Runway::Runway(char* definition)
@@ -65,13 +66,13 @@ Runway::Runway(char* definition)
         >> rwy.reil[1];
 
     // calculate runway heading and length (used a lot)
-    SGGeodesy::inverse( GetStart(), GetEnd(), rwy.heading, az2, rwy.length );
+    SGGeodesy::inverse(GetStart(), GetEnd(), rwy.heading, az2, rwy.length);
 
     TG_LOG(SG_GENERAL, SG_DEBUG, "Read runway: (" << rwy.lon[0] << "," << rwy.lat[0] <<
-            ") to (" << rwy.lon[1] << "," << rwy.lat[1] <<
-            ") heading: " << rwy.heading <<
-            " length: " << rwy.length <<
-            " width: " << rwy.width );
+                                 ") to (" << rwy.lon[1] << "," << rwy.lat[1] <<
+                                 ") heading: " << rwy.heading <<
+                                 " length: " << rwy.length <<
+                                 " width: " << rwy.width );
 } 
 
 
@@ -87,14 +88,17 @@ WaterRunway::WaterRunway(char* definition)
         >> lat[1]
         >> lon[1];
 
-    TG_LOG(SG_GENERAL, SG_DEBUG, "Read water runway: (" << lon[0] << "," << lat[0] << ") to (" << lon[1] << "," << lat[1] << ") width: " << width << " buoys = " << buoys );
+    TG_LOG(SG_GENERAL, SG_DEBUG, "Read water runway: (" << lon[0] << "," << lat[0] <<
+                                 ") to (" << lon[1] << "," << lat[1] <<
+                                 ") width: " << width <<
+                                 " buoys = " << buoys);
 }
 
 tgContour WaterRunway::GetBuoys()
 {
     tgContour buoys_nodes;
 
-    if (buoys){
+    if (buoys) {
         double heading, az2, length;
         // calculate runway heading and length
         SGGeodesy::inverse(GetStart(), GetEnd(), heading, az2, length);
@@ -102,15 +106,16 @@ tgContour WaterRunway::GetBuoys()
         // create a contour with points every 100m
         tgContour area = gen_wgs84_area(GetStart(), GetEnd(),
                                         0, 0, 0, width, heading, false);
-        for ( unsigned int i = 0; i < area.GetSize(); ++i ) {
+
+        for (unsigned int i = 0; i < area.GetSize(); ++i) {
             double dist, course, cs;
-            SGGeodesy::inverse(area.GetNode(i), area.GetNode(i==3 ? 0 : i+1), course, cs, dist );
+            SGGeodesy::inverse(area.GetNode(i), area.GetNode(i == 3 ? 0 : i + 1), course, cs, dist);
             int divs = (int)(dist / 100.0);
-            double step = dist/divs;
+            double step = dist / divs;
             SGGeod pt = area.GetNode(i);
             for (int j = 0; j < divs; ++j) {
-                pt = SGGeodesy::direct(pt, course, step );
-                buoys_nodes.AddNode( pt );
+                pt = SGGeodesy::direct(pt, course, step);
+                buoys_nodes.AddNode(pt);
             }
         }
     }
@@ -118,114 +123,102 @@ tgContour WaterRunway::GetBuoys()
     return buoys_nodes;
 }
 
-int Runway::BuildBtg( tgpolygon_list& rwy_polys, tglightcontour_list& rwy_lights, tgcontour_list& slivers, tgAccumulator& accum, std::string& shapefile_name )
+int Runway::BuildBtg(tgpolygon_list& rwy_polys, tglightcontour_list& rwy_lights, tgcontour_list& slivers, tgAccumulator& accum, std::string& shapefile_name)
 {
-    if ( rwy.surface == 1 /* Asphalt */ )
-    {
+    if (rwy.surface == 1 /* Asphalt */) {
         material_prefix = "pa_";
-    }
-    else if ( rwy.surface == 2 /* Concrete */ )
-    {
+    } else if (rwy.surface == 2 /* Concrete */) {
         material_prefix = "pc_";
-    }
-    else if ( rwy.surface == 3 /* Turf/Grass */ )
-    {
+    } else if (rwy.surface == 3 /* Turf/Grass */) {
         material_prefix = "grass_rwy";
-    }
-    else if ( rwy.surface == 4 /* Dirt */ || rwy.surface == 5 /* Gravel */ )
-    {
+    } else if (rwy.surface == 4 /* Dirt */ || rwy.surface == 5 /* Gravel */) {
         material_prefix = "dirt_rwy";
-    }
-    else if ( rwy.surface == 12 /* Dry Lakebed */ )
-    {
+    } else if (rwy.surface == 12 /* Dry Lakebed */) {
         material_prefix = "lakebed_taxiway";
-    }
-    else if ( rwy.surface == 13 /* Water runway (buoys) */ )
-    {
+    } else if (rwy.surface == 13 /* Water runway (buoys) */) {
         // water
-    }
-    else if ( rwy.surface == 14 /* Snow / Ice */ )
-    {
+    } else if (rwy.surface == 14 /* Snow / Ice */) {
         // Ice
-    }
-    else if ( rwy.surface == 15 /* Transparent */ )
-    {
+    } else if (rwy.surface == 15 /* Transparent */) {
         //Transparent texture
-    }
-    else
-    {
+    } else {
         TG_LOG(SG_GENERAL, SG_WARN, "surface_code = " << rwy.surface);
         throw sg_exception("unknown runway type!");
     }
 
     // first, check the surface type - anything but concrete and asphalt are easy
-    switch( rwy.surface )
-    {
-        case 1: // asphalt:
-        case 2: // concrete
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: asphalt or concrete " << rwy.surface);
-            gen_rwy( rwy_polys, slivers, accum, shapefile_name );
-            gen_runway_lights( rwy_lights );
-            break;
+    switch (rwy.surface) {
+    case 1: // asphalt:
+    case 2: // concrete
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: asphalt or concrete " << rwy.surface);
+        gen_rwy(rwy_polys, slivers, accum, shapefile_name);
+        gen_runway_lights(rwy_lights);
+        break;
 
-        case 3: // Grass
-        case 4: // Dirt
-        case 5: // Gravel
-        case 12: // dry lakebed
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: Grass, Dirt, Gravel or Dry Lakebed " << rwy.surface );
-            gen_simple_rwy( rwy_polys, slivers, accum );
-            gen_runway_lights( rwy_lights );
-            break;
+    case 3:  // Grass
+    case 4:  // Dirt
+    case 5:  // Gravel
+    case 12: // dry lakebed
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: Grass, Dirt, Gravel or Dry Lakebed " << rwy.surface);
+        gen_simple_rwy(rwy_polys, slivers, accum);
+        gen_runway_lights(rwy_lights);
+        break;
 
-        case 13: // water
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: Water");
-            break;
+    case 13: // water
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: Water");
+        break;
 
-        case 14: // snow
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: Snow");
-            break;
+    case 14: // snow
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: Snow");
+        break;
 
-        case 15: // transparent
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: transparent");
-            break;
+    case 15: // transparent
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: transparent");
+        break;
 
-        default: // unknown
-            TG_LOG( SG_GENERAL, SG_DEBUG, "Build Runway: unknown: " << rwy.surface);
-            break;
+    default: // unknown
+        TG_LOG(SG_GENERAL, SG_DEBUG, "Build Runway: unknown: " << rwy.surface);
+        break;
     }
 
     return 0;
 }
 
-int Runway::BuildBtg( tgpolygon_list& rwy_polys, tglightcontour_list& rwy_lights, tgcontour_list& slivers, tgpolygon_list& apt_base_polys, tgpolygon_list& apt_clearing_polys, tgAccumulator& accum, std::string& shapefile_name )
+int Runway::BuildBtg(tgpolygon_list& rwy_polys,
+                     tglightcontour_list& rwy_lights,
+                     tgcontour_list& slivers,
+                     tgpolygon_list& apt_base_polys,
+                     tgpolygon_list& apt_clearing_polys,
+                     tgAccumulator& accum,
+                     std::string& shapefile_name)
 {
     tgContour base_contour, safe_base_contour;
     tgPolygon base, safe_base;
     double shoulder_width = 0.0;
 
-    BuildBtg( rwy_polys, rwy_lights, slivers, accum, shapefile_name );
+    BuildBtg(rwy_polys, rwy_lights, slivers, accum, shapefile_name);
 
     // generate area around runways
-    if ( (rwy.shoulder > 0) && (rwy.surface < 3) ) {
+    if ((rwy.shoulder > 0) && (rwy.surface < 3)) {
         shoulder_width += 22.0;
-    } else if ( (rwy.surface == 1) || (rwy.surface == 2) ) {
+    } else if ((rwy.surface == 1) || (rwy.surface == 2)) {
         shoulder_width += 2.0;
     }
 
-    base_contour      = gen_runway_area_w_extend( 20.0, -rwy.overrun[0], -rwy.overrun[1], shoulder_width + 20.0 );
-    base_contour      = tgContour::Snap( base_contour, gSnap );
-    base.AddContour( base_contour );
+    base_contour = gen_runway_area_w_extend(20.0, -rwy.overrun[0], -rwy.overrun[1], shoulder_width + 20.0);
+    base_contour = tgContour::Snap(base_contour, gSnap);
+    base.AddContour(base_contour);
 
     // also clear a safe area around the runway
-    safe_base_contour = gen_runway_area_w_extend( 180.0, -rwy.overrun[0], -rwy.overrun[1], shoulder_width + 50.0 );
-    safe_base_contour = tgContour::Snap( safe_base_contour, gSnap );
-    safe_base.AddContour( safe_base_contour );
+    safe_base_contour = gen_runway_area_w_extend(180.0, -rwy.overrun[0], -rwy.overrun[1], shoulder_width + 50.0);
+    safe_base_contour = tgContour::Snap(safe_base_contour, gSnap);
+    safe_base.AddContour(safe_base_contour);
 
     // add this to the airport clearing
-    apt_clearing_polys.push_back( safe_base );
+    apt_clearing_polys.push_back(safe_base);
 
     // and add the clearing to the base
-    apt_base_polys.push_back( base );
+    apt_base_polys.push_back(base);
 
     return 0;
 }
diff --git a/src/Airports/GenAirports/runway.hxx b/src/Airports/GenAirports/runway.hxx
index 99f10193..89691177 100644
--- a/src/Airports/GenAirports/runway.hxx
+++ b/src/Airports/GenAirports/runway.hxx
@@ -14,22 +14,22 @@ class Runway
 public:
     explicit Runway(char* def);
 
-    SGGeod GetStart()
+    SGGeod GetStart() const
     {
         return SGGeod::fromDeg(rwy.lon[0], rwy.lat[0]);
     }
 
-    SGGeod GetEnd()
+    SGGeod GetEnd() const
     {
         return SGGeod::fromDeg(rwy.lon[1], rwy.lat[1]);
     }
 
-    SGGeod GetMidpoint()
+    SGGeod GetMidpoint() const
     {
         return SGGeod::fromDeg((rwy.lon[0] + rwy.lon[1]) / 2.0f, (rwy.lat[0] + rwy.lat[1]) / 2.0f);
     }
 
-    bool GetsShoulder()
+    bool GetsShoulder() const
     {
         return (rwy.surface < 3) ? true : false;
     }
@@ -54,7 +54,7 @@ public:
 
 private:
     struct TGRunway {
-        // data for whole runway
+        // data for the whole runway
         int surface;
         int shoulder;
         int centerline_lights;
@@ -187,12 +187,12 @@ public:
 
     tgContour GetBuoys();
 
-    SGGeod GetStart(void)
+    SGGeod GetStart() const
     {
         return SGGeod::fromDeg(lon[0], lat[0]);
     }
 
-    SGGeod GetEnd(void)
+    SGGeod GetEnd() const
     {
         return SGGeod::fromDeg(lon[1], lat[1]);
     }
@@ -204,4 +204,5 @@ private:
     double lat[2];
     double lon[2];
 };
+
 typedef std::vector<std::shared_ptr<WaterRunway>> WaterRunwayList;