diff --git a/src/drt/src/gr/FlexGR.cpp b/src/drt/src/gr/FlexGR.cpp
index ae59df258b9..e81ac292e7a 100644
--- a/src/drt/src/gr/FlexGR.cpp
+++ b/src/drt/src/gr/FlexGR.cpp
@@ -2524,7 +2524,7 @@ void FlexGR::updateDb()
              lNum += 2) {
           auto layer = design_->getTech()->getLayer(lNum);
           auto dbLayer = dbTech->findLayer(layer->getName().c_str());
-          odb::dbGuide::create(dbNet, dbLayer, bbox);
+          odb::dbGuide::create(dbNet, dbLayer, dbLayer, bbox);
         }
       } else {
         auto layer = design_->getTech()->getLayer(bNum);
@@ -2532,6 +2532,7 @@ void FlexGR::updateDb()
         odb::dbGuide::create(
             dbNet,
             dbLayer,
+            dbLayer,
             {bbox.xMin(), bbox.yMin(), ebox.xMax(), ebox.yMax()});
       }
     }
diff --git a/src/drt/src/io/GuideProcessor.cpp b/src/drt/src/io/GuideProcessor.cpp
index c616f68dc12..4a9773f2ee0 100644
--- a/src/drt/src/io/GuideProcessor.cpp
+++ b/src/drt/src/io/GuideProcessor.cpp
@@ -1846,6 +1846,7 @@ void GuideProcessor::saveGuidesUpdates()
           odb::dbGuide::create(
               dbNet,
               dbLayer,
+              dbLayer,
               {bbox.xMin(), bbox.yMin(), ebox.xMax(), ebox.yMax()});
         }
       } else {
@@ -1854,6 +1855,7 @@ void GuideProcessor::saveGuidesUpdates()
         odb::dbGuide::create(
             dbNet,
             dbLayer,
+            dbLayer,
             {bbox.xMin(), bbox.yMin(), ebox.xMax(), ebox.yMax()});
       }
     }
diff --git a/src/drt/test/ispd18_sample.ok b/src/drt/test/ispd18_sample.ok
index 52cffa839b9..c8d9351b70c 100644
--- a/src/drt/test/ispd18_sample.ok
+++ b/src/drt/test/ispd18_sample.ok
@@ -2,6 +2,7 @@
 [INFO ODB-0128] Design: ispd18_sample
 [INFO ODB-0131]     Created 22 components and 146 component-terminals.
 [INFO ODB-0133]     Created 11 nets and 22 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0160] Warning: Metal5 does not have viaDef aligned with layer direction, generating new viaDef Via5_FR.
 [WARNING DRT-0160] Warning: Metal6 does not have viaDef aligned with layer direction, generating new viaDef Via6_FR.
 [WARNING DRT-0160] Warning: Metal7 does not have viaDef aligned with layer direction, generating new viaDef Via7_FR.
diff --git a/src/drt/test/ispd18_sample_incr.ok b/src/drt/test/ispd18_sample_incr.ok
index 4924dcfbeef..7aa131bc2b1 100644
--- a/src/drt/test/ispd18_sample_incr.ok
+++ b/src/drt/test/ispd18_sample_incr.ok
@@ -2,6 +2,7 @@
 [INFO ODB-0128] Design: ispd18_sample
 [INFO ODB-0131]     Created 22 components and 146 component-terminals.
 [INFO ODB-0133]     Created 11 nets and 22 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0160] Warning: Metal5 does not have viaDef aligned with layer direction, generating new viaDef Via5_FR.
 [WARNING DRT-0160] Warning: Metal6 does not have viaDef aligned with layer direction, generating new viaDef Via6_FR.
 [WARNING DRT-0160] Warning: Metal7 does not have viaDef aligned with layer direction, generating new viaDef Via7_FR.
diff --git a/src/drt/test/ndr_vias1.ok b/src/drt/test/ndr_vias1.ok
index ad8ce8ad5b2..f66ef2baa0f 100644
--- a/src/drt/test/ndr_vias1.ok
+++ b/src/drt/test/ndr_vias1.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 66 components and 347 component-terminals.
 [INFO ODB-0133]     Created 8 nets and 54 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer via
diff --git a/src/drt/test/ndr_vias2.ok b/src/drt/test/ndr_vias2.ok
index 4336794a5d7..2b97f82f653 100644
--- a/src/drt/test/ndr_vias2.ok
+++ b/src/drt/test/ndr_vias2.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 66 components and 347 component-terminals.
 [INFO ODB-0133]     Created 8 nets and 54 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer via
diff --git a/src/drt/test/obstruction.ok b/src/drt/test/obstruction.ok
index bb050813f66..8a0bdd09972 100644
--- a/src/drt/test/obstruction.ok
+++ b/src/drt/test/obstruction.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 4 components and 24 component-terminals.
 [INFO ODB-0133]     Created 1 nets and 4 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer via
diff --git a/src/drt/test/single_step.ok b/src/drt/test/single_step.ok
index 52cffa839b9..c8d9351b70c 100644
--- a/src/drt/test/single_step.ok
+++ b/src/drt/test/single_step.ok
@@ -2,6 +2,7 @@
 [INFO ODB-0128] Design: ispd18_sample
 [INFO ODB-0131]     Created 22 components and 146 component-terminals.
 [INFO ODB-0133]     Created 11 nets and 22 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0160] Warning: Metal5 does not have viaDef aligned with layer direction, generating new viaDef Via5_FR.
 [WARNING DRT-0160] Warning: Metal6 does not have viaDef aligned with layer direction, generating new viaDef Via6_FR.
 [WARNING DRT-0160] Warning: Metal7 does not have viaDef aligned with layer direction, generating new viaDef Via7_FR.
diff --git a/src/drt/test/ta_ap_aligned.ok b/src/drt/test/ta_ap_aligned.ok
index dc4ab005e43..90bcb8927c7 100644
--- a/src/drt/test/ta_ap_aligned.ok
+++ b/src/drt/test/ta_ap_aligned.ok
@@ -3,6 +3,7 @@
 [INFO ODB-0128] Design: test
 [INFO ODB-0131]     Created 4 components and 16 component-terminals.
 [INFO ODB-0133]     Created 2 nets and 4 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO DRT-0167] List of default vias:
   Layer via1
     default via: via1_7
diff --git a/src/drt/test/ta_pin_aligned.ok b/src/drt/test/ta_pin_aligned.ok
index b0fc2a1e300..3caf0fc9034 100644
--- a/src/drt/test/ta_pin_aligned.ok
+++ b/src/drt/test/ta_pin_aligned.ok
@@ -3,6 +3,7 @@
 [INFO ODB-0128] Design: test
 [INFO ODB-0130]     Created 4 pins.
 [INFO ODB-0133]     Created 2 nets and 0 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO DRT-0167] List of default vias:
   Layer via1
     default via: via1_7
diff --git a/src/drt/test/top_level_term.ok b/src/drt/test/top_level_term.ok
index e247f20f16b..bf6b3240fc5 100644
--- a/src/drt/test/top_level_term.ok
+++ b/src/drt/test/top_level_term.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 4 components and 24 component-terminals.
 [INFO ODB-0133]     Created 1 nets and 4 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer via
diff --git a/src/drt/test/top_level_term2.ok b/src/drt/test/top_level_term2.ok
index 2bedc1b2d08..6b027348f3a 100644
--- a/src/drt/test/top_level_term2.ok
+++ b/src/drt/test/top_level_term2.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 3 pins.
 [INFO ODB-0131]     Created 4 components and 24 component-terminals.
 [INFO ODB-0133]     Created 1 nets and 4 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer mcon
 [WARNING DRT-0349] LEF58_ENCLOSURE with no CUTCLASS is not supported. Skipping for layer via
diff --git a/src/grt/include/grt/GlobalRouter.h b/src/grt/include/grt/GlobalRouter.h
index 4bf7271fa61..5cff944376c 100644
--- a/src/grt/include/grt/GlobalRouter.h
+++ b/src/grt/include/grt/GlobalRouter.h
@@ -277,7 +277,10 @@ class GlobalRouter : public ant::GlobalRouteSource
   void reportNetLayerWirelengths(odb::dbNet* db_net, std::ofstream& out);
   void reportLayerWireLengths();
   odb::Rect globalRoutingToBox(const GSegment& route);
-  void boxToGlobalRouting(const odb::Rect& route_bds, int layer, GRoute& route);
+  void boxToGlobalRouting(const odb::Rect& route_bds,
+                          int layer,
+                          int via_layer,
+                          GRoute& route);
   void updateVias();
 
   // Report wire length
@@ -372,8 +375,6 @@ class GlobalRouter : public ant::GlobalRouteSource
                           int min_routing_layer,
                           int max_routing_layer);
   void connectPadPins(NetRouteMap& routes);
-  void mergeBox(std::vector<odb::Rect>& guide_box,
-                const std::set<odb::Point>& via_positions);
   bool segmentsConnect(const GSegment& seg0,
                        const GSegment& seg1,
                        GSegment& new_seg,
diff --git a/src/grt/src/GlobalRouter.cpp b/src/grt/src/GlobalRouter.cpp
index c72b592bdfe..12218f7da3d 100644
--- a/src/grt/src/GlobalRouter.cpp
+++ b/src/grt/src/GlobalRouter.cpp
@@ -229,6 +229,7 @@ void GlobalRouter::saveCongestion()
 
 bool GlobalRouter::haveRoutes()
 {
+  loadGuidesFromDB();
   if (routes_.empty()) {
     logger_->warn(GRT, 97, "No global routing found for nets.");
   }
@@ -1894,6 +1895,10 @@ void GlobalRouter::checkOverflow()
 
 void GlobalRouter::readGuides(const char* file_name)
 {
+  logger_->warn(GRT,
+                8,
+                "The read_guides command does not allow parasitics estimation "
+                "from the guides file.");
   if (db_->getChip() == nullptr || db_->getChip()->getBlock() == nullptr
       || db_->getTech() == nullptr) {
     logger_->error(GRT, 249, "Load design before reading guides");
@@ -1958,7 +1963,8 @@ void GlobalRouter::readGuides(const char* file_name)
       odb::Rect rect(
           stoi(tokens[0]), stoi(tokens[1]), stoi(tokens[2]), stoi(tokens[3]));
       guides[net].push_back(std::make_pair(layer->getRoutingLevel(), rect));
-      boxToGlobalRouting(rect, layer->getRoutingLevel(), routes_[net]);
+      int layer_idx = layer->getRoutingLevel();
+      boxToGlobalRouting(rect, layer_idx, layer_idx, routes_[net]);
     } else {
       logger_->error(GRT, 236, "Error reading guide file {}.", file_name);
     }
@@ -1981,16 +1987,19 @@ void GlobalRouter::readGuides(const char* file_name)
 
 void GlobalRouter::loadGuidesFromDB()
 {
+  if (!routes_.empty()) {
+    return;
+  }
   initGridAndNets();
   for (odb::dbNet* net : block_->getNets()) {
     for (odb::dbGuide* guide : net->getGuides()) {
+      int layer_idx = guide->getLayer()->getRoutingLevel();
+      int via_layer_idx = guide->getViaLayer()->getRoutingLevel();
       boxToGlobalRouting(
-          guide->getBox(), guide->getLayer()->getRoutingLevel(), routes_[net]);
+          guide->getBox(), layer_idx, via_layer_idx, routes_[net]);
     }
   }
 
-  updateVias();
-
   for (auto& net_route : routes_) {
     std::vector<Pin>& pins = db_net_map_[net_route.first]->getPins();
     GRoute& route = net_route.second;
@@ -2199,7 +2208,8 @@ void GlobalRouter::saveGuidesFromFile(
     if (!guide_boxes.empty()) {
       for (const auto& guide : guide_boxes) {
         ph_layer_final = routing_layers_[guide.first];
-        odb::dbGuide::create(db_net, ph_layer_final, guide.second);
+        odb::dbGuide::create(
+            db_net, ph_layer_final, ph_layer_final, guide.second);
       }
     }
   }
@@ -2236,12 +2246,15 @@ void GlobalRouter::saveGuides()
             int layer_idx2 = segment.final_layer;
             odb::dbTechLayer* layer1 = routing_layers_[layer_idx1];
             odb::dbTechLayer* layer2 = routing_layers_[layer_idx2];
-            odb::dbGuide::create(db_net, layer1, box);
-            odb::dbGuide::create(db_net, layer2, box);
+            odb::dbGuide::create(db_net, layer1, layer2, box);
+            odb::dbGuide::create(db_net, layer2, layer1, box);
           } else {
             int layer_idx = std::min(segment.init_layer, segment.final_layer);
-            odb::dbTechLayer* layer1 = routing_layers_[layer_idx];
-            odb::dbGuide::create(db_net, layer1, box);
+            int via_layer_idx
+                = std::max(segment.init_layer, segment.final_layer);
+            odb::dbTechLayer* layer = routing_layers_[layer_idx];
+            odb::dbTechLayer* via_layer = routing_layers_[via_layer_idx];
+            odb::dbGuide::create(db_net, layer, via_layer, box);
           }
         } else if (segment.init_layer == segment.final_layer) {
           if (segment.init_layer < min_routing_layer_
@@ -2254,7 +2267,7 @@ void GlobalRouter::saveGuides()
           }
 
           odb::dbTechLayer* layer = routing_layers_[segment.init_layer];
-          odb::dbGuide::create(db_net, layer, box);
+          odb::dbGuide::create(db_net, layer, layer, box);
         }
       }
     }
@@ -2640,63 +2653,15 @@ void GlobalRouter::connectPadPins(NetRouteMap& routes)
   }
 }
 
-void GlobalRouter::mergeBox(std::vector<odb::Rect>& guide_box,
-                            const std::set<odb::Point>& via_positions)
-{
-  std::vector<odb::Rect> final_box;
-  if (guide_box.empty()) {
-    logger_->error(GRT, 78, "Guides vector is empty.");
-  }
-  final_box.push_back(guide_box[0]);
-  for (size_t i = 1; i < guide_box.size(); i++) {
-    odb::Rect box = guide_box[i];
-    odb::Rect& lastBox = final_box.back();
-
-    GRoute segs;
-    boxToGlobalRouting(box, 0, segs);
-    odb::Point seg_init(segs[0].init_x, segs[0].init_y);
-    odb::Point seg_final(segs.back().init_x, segs.back().init_y);
-
-    if (lastBox.overlaps(box)
-        && (via_positions.find(seg_init) == via_positions.end()
-            || via_positions.find(seg_final) == via_positions.end())) {
-      int lowerX = std::min(lastBox.xMin(), box.xMin());
-      int lowerY = std::min(lastBox.yMin(), box.yMin());
-      int upperX = std::max(lastBox.xMax(), box.xMax());
-      int upperY = std::max(lastBox.yMax(), box.yMax());
-      lastBox = odb::Rect(lowerX, lowerY, upperX, upperY);
-    } else
-      final_box.push_back(box);
-  }
-  guide_box.clear();
-  guide_box = std::move(final_box);
-}
-
 odb::Rect GlobalRouter::globalRoutingToBox(const GSegment& route)
 {
   odb::Rect die_bounds = grid_->getGridArea();
-  int init_x, init_y;
-  int final_x, final_y;
 
-  if (route.init_x < route.final_x) {
-    init_x = route.init_x;
-    final_x = route.final_x;
-  } else {
-    init_x = route.final_x;
-    final_x = route.init_x;
-  }
-
-  if (route.init_y < route.final_y) {
-    init_y = route.init_y;
-    final_y = route.final_y;
-  } else {
-    init_y = route.final_y;
-    final_y = route.init_y;
-  }
+  const auto [init_x, final_x] = std::minmax(route.init_x, route.final_x);
+  const auto [init_y, final_y] = std::minmax(route.init_y, route.final_y);
 
   int llX = init_x - (grid_->getTileSize() / 2);
   int llY = init_y - (grid_->getTileSize() / 2);
-
   int urX = final_x + (grid_->getTileSize() / 2);
   int urY = final_y + (grid_->getTileSize() / 2);
 
@@ -2716,6 +2681,7 @@ odb::Rect GlobalRouter::globalRoutingToBox(const GSegment& route)
 
 void GlobalRouter::boxToGlobalRouting(const odb::Rect& route_bds,
                                       int layer,
+                                      int via_layer,
                                       GRoute& route)
 {
   const int tile_size = grid_->getTileSize();
@@ -2725,8 +2691,9 @@ void GlobalRouter::boxToGlobalRouting(const odb::Rect& route_bds,
   const int x1 = (tile_size * (route_bds.xMax() / tile_size)) - (tile_size / 2);
   const int y1 = (tile_size * (route_bds.yMax() / tile_size)) - (tile_size / 2);
 
-  if (x0 == x1 && y0 == y1)
-    route.push_back(GSegment(x0, y0, layer, x1, y1, layer));
+  if (x0 == x1 && y0 == y1) {
+    route.push_back(GSegment(x0, y0, layer, x1, y1, via_layer));
+  }
 
   while (y0 == y1 && (x0 + tile_size) <= x1) {
     route.push_back(GSegment(x0, y0, layer, x0 + tile_size, y0, layer));
diff --git a/src/grt/src/GlobalRouter.tcl b/src/grt/src/GlobalRouter.tcl
index 4536cb35fbf..0e9eb0dbfc8 100644
--- a/src/grt/src/GlobalRouter.tcl
+++ b/src/grt/src/GlobalRouter.tcl
@@ -374,6 +374,7 @@ proc read_guides { args } {
     keys {} \
     flags {}
   set file_name $args
+
   grt::read_guides $file_name
 }
 
diff --git a/src/grt/test/est_rc3.ok b/src/grt/test/est_rc3.ok
index 848c894c589..7c0c5dedb2c 100644
--- a/src/grt/test/est_rc3.ok
+++ b/src/grt/test/est_rc3.ok
@@ -3,6 +3,7 @@
 [INFO ODB-0130]     Created 54 pins.
 [INFO ODB-0131]     Created 676 components and 2850 component-terminals.
 [INFO ODB-0133]     Created 579 nets and 1498 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 Net clk
  Pin capacitance: 29.975-33.238
  Wire capacitance: 17.722-17.722
diff --git a/src/grt/test/est_rc4.ok b/src/grt/test/est_rc4.ok
index faec19fb189..2f2eb49acc7 100644
--- a/src/grt/test/est_rc4.ok
+++ b/src/grt/test/est_rc4.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 54 pins.
 [INFO ODB-0131]     Created 676 components and 2850 component-terminals.
 [INFO ODB-0133]     Created 579 nets and 1498 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 Net clk
  Pin capacitance: 29.975-33.238
  Wire capacitance: 330.569
diff --git a/src/grt/test/report_wire_length1.ok b/src/grt/test/report_wire_length1.ok
index 2424d57f1c9..49d5b925ca6 100644
--- a/src/grt/test/report_wire_length1.ok
+++ b/src/grt/test/report_wire_length1.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 170 components and 1258 component-terminals.
 [INFO ODB-0133]     Created 15 nets and 72 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net clk global route wire length: 201.60um
 [INFO GRT-0240] Net clk detailed route wire length: 184.95um
 [INFO GRT-0237] Net net60 global route wire length: 14.40um
diff --git a/src/grt/test/report_wire_length2.ok b/src/grt/test/report_wire_length2.ok
index 6754265ee0e..4702cd7e471 100644
--- a/src/grt/test/report_wire_length2.ok
+++ b/src/grt/test/report_wire_length2.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 170 components and 1258 component-terminals.
 [INFO ODB-0133]     Created 15 nets and 72 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net clk global route wire length: 201.60um
 [INFO GRT-0240] Net clk detailed route wire length: 184.95um
 [INFO GRT-0237] Net clknet_0_clk global route wire length: 93.60um
diff --git a/src/grt/test/report_wire_length3.ok b/src/grt/test/report_wire_length3.ok
index e76bb37753f..034dfd6db4b 100644
--- a/src/grt/test/report_wire_length3.ok
+++ b/src/grt/test/report_wire_length3.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 170 components and 1258 component-terminals.
 [INFO ODB-0133]     Created 15 nets and 72 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net clk global route wire length: 201.60um
 	Layer met3 : 144.00um
 	Layer met4 : 57.60um
diff --git a/src/grt/test/report_wire_length4.ok b/src/grt/test/report_wire_length4.ok
index 7ba62bcc58d..e59bd79dbef 100644
--- a/src/grt/test/report_wire_length4.ok
+++ b/src/grt/test/report_wire_length4.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 170 components and 1258 component-terminals.
 [INFO ODB-0133]     Created 15 nets and 72 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net clk global route wire length: 201.60um
 	Layer met3 : 144.00um
 	Layer met4 : 57.60um
diff --git a/src/grt/test/report_wire_length5.ok b/src/grt/test/report_wire_length5.ok
index 211058665fa..fcbfb52b87e 100644
--- a/src/grt/test/report_wire_length5.ok
+++ b/src/grt/test/report_wire_length5.ok
@@ -4,6 +4,7 @@
 [INFO ODB-0130]     Created 1 pins.
 [INFO ODB-0131]     Created 170 components and 1258 component-terminals.
 [INFO ODB-0133]     Created 15 nets and 72 connections.
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net clk global route wire length: 201.60um
 [INFO GRT-0240] Net clk detailed route wire length: 184.95um
 [INFO GRT-0237] Net net60 global route wire length: 14.40um
diff --git a/src/grt/test/report_wire_length6.ok b/src/grt/test/report_wire_length6.ok
index 8238a5fe00b..c11fec188ba 100644
--- a/src/grt/test/report_wire_length6.ok
+++ b/src/grt/test/report_wire_length6.ok
@@ -6,5 +6,6 @@
 [INFO ODB-0131]     Created 6 components and 29 component-terminals.
 [INFO ODB-0133]     Created 2 nets and 6 connections.
 [INFO ODB-0134] Finished DEF file: report_wire_length6.def
+[WARNING GRT-0008] The read_guides command does not allow parasitics estimation from the guides file.
 [INFO GRT-0237] Net o[4] global route wire length: 15.12um
 [INFO GRT-0237] Net final_adder.$signal$2073 global route wire length: 5.40um
diff --git a/src/odb/include/odb/db.h b/src/odb/include/odb/db.h
index 4e85b608410..82325c7d019 100644
--- a/src/odb/include/odb/db.h
+++ b/src/odb/include/odb/db.h
@@ -7501,7 +7501,12 @@ class dbGuide : public dbObject
 
   dbTechLayer* getLayer() const;
 
-  static dbGuide* create(dbNet* net, dbTechLayer* layer, Rect box);
+  dbTechLayer* getViaLayer() const;
+
+  static dbGuide* create(dbNet* net,
+                         dbTechLayer* layer,
+                         dbTechLayer* via_layer,
+                         Rect box);
 
   static dbGuide* getGuide(dbBlock* block, uint dbid);
 
diff --git a/src/odb/src/codeGenerator/schema/chip/dbGuide.json b/src/odb/src/codeGenerator/schema/chip/dbGuide.json
index 4973b9bc827..579f51cca17 100644
--- a/src/odb/src/codeGenerator/schema/chip/dbGuide.json
+++ b/src/odb/src/codeGenerator/schema/chip/dbGuide.json
@@ -22,6 +22,14 @@
           "private"
         ]
       },
+      {
+        "name": "via_layer_",
+        "type": "dbId<_dbTechLayer>",
+        "schema":"db_schema_db_guide_via_layer",
+        "flags": [
+          "private"
+        ]
+      },
       {
         "name":"guide_next_",
         "type":"dbId<_dbGuide>",
diff --git a/src/odb/src/db/dbDatabase.h b/src/odb/src/db/dbDatabase.h
index 09dc3190c6c..d9c21a9091e 100644
--- a/src/odb/src/db/dbDatabase.h
+++ b/src/odb/src/db/dbDatabase.h
@@ -70,7 +70,10 @@ namespace odb {
 const uint db_schema_major = 0;  // Not used...
 const uint db_schema_initial = 57;
 
-const uint db_schema_minor = 89;  // Current revision number
+const uint db_schema_minor = 90;  // Current revision number
+
+// Revision where via layer was added to dbGuide
+const uint db_schema_db_guide_via_layer = 90;
 
 // Revision where blocked regions for IO pins were added to dbBlock
 const uint db_schema_dbblock_blocked_regions_for_pins = 89;
diff --git a/src/odb/src/db/dbGuide.cpp b/src/odb/src/db/dbGuide.cpp
index 7ba1d0fdc76..c7068d763c8 100644
--- a/src/odb/src/db/dbGuide.cpp
+++ b/src/odb/src/db/dbGuide.cpp
@@ -58,6 +58,9 @@ bool _dbGuide::operator==(const _dbGuide& rhs) const
   if (layer_ != rhs.layer_) {
     return false;
   }
+  if (via_layer_ != rhs.via_layer_) {
+    return false;
+  }
   if (guide_next_ != rhs.guide_next_) {
     return false;
   }
@@ -78,6 +81,7 @@ void _dbGuide::differences(dbDiff& diff,
   DIFF_FIELD(net_);
   DIFF_FIELD(box_);
   DIFF_FIELD(layer_);
+  DIFF_FIELD(via_layer_);
   DIFF_FIELD(guide_next_);
   DIFF_END
 }
@@ -88,6 +92,7 @@ void _dbGuide::out(dbDiff& diff, char side, const char* field) const
   DIFF_OUT_FIELD(net_);
   DIFF_OUT_FIELD(box_);
   DIFF_OUT_FIELD(layer_);
+  DIFF_OUT_FIELD(via_layer_);
   DIFF_OUT_FIELD(guide_next_);
 
   DIFF_END
@@ -102,6 +107,7 @@ _dbGuide::_dbGuide(_dbDatabase* db, const _dbGuide& r)
   net_ = r.net_;
   box_ = r.box_;
   layer_ = r.layer_;
+  via_layer_ = r.via_layer_;
   guide_next_ = r.guide_next_;
 }
 
@@ -110,6 +116,9 @@ dbIStream& operator>>(dbIStream& stream, _dbGuide& obj)
   stream >> obj.net_;
   stream >> obj.box_;
   stream >> obj.layer_;
+  if (obj.getDatabase()->isSchema(db_schema_db_guide_via_layer)) {
+    stream >> obj.via_layer_;
+  }
   stream >> obj.guide_next_;
   return stream;
 }
@@ -119,6 +128,9 @@ dbOStream& operator<<(dbOStream& stream, const _dbGuide& obj)
   stream << obj.net_;
   stream << obj.box_;
   stream << obj.layer_;
+  if (obj.getDatabase()->isSchema(db_schema_db_guide_via_layer)) {
+    stream << obj.via_layer_;
+  }
   stream << obj.guide_next_;
   return stream;
 }
@@ -144,6 +156,13 @@ dbTechLayer* dbGuide::getLayer() const
   return odb::dbTechLayer::getTechLayer(tech, obj->layer_);
 }
 
+dbTechLayer* dbGuide::getViaLayer() const
+{
+  _dbGuide* obj = (_dbGuide*) this;
+  auto tech = getDb()->getTech();
+  return odb::dbTechLayer::getTechLayer(tech, obj->via_layer_);
+}
+
 dbNet* dbGuide::getNet() const
 {
   _dbGuide* obj = (_dbGuide*) this;
@@ -151,7 +170,10 @@ dbNet* dbGuide::getNet() const
   return (dbNet*) block->_net_tbl->getPtr(obj->net_);
 }
 
-dbGuide* dbGuide::create(dbNet* net, dbTechLayer* layer, Rect box)
+dbGuide* dbGuide::create(dbNet* net,
+                         dbTechLayer* layer,
+                         dbTechLayer* via_layer,
+                         Rect box)
 {
   _dbNet* owner = (_dbNet*) net;
   _dbBlock* block = (_dbBlock*) owner->getOwner();
@@ -172,6 +194,7 @@ dbGuide* dbGuide::create(dbNet* net, dbTechLayer* layer, Rect box)
   }
 
   guide->layer_ = layer->getImpl()->getOID();
+  guide->via_layer_ = via_layer->getImpl()->getOID();
   guide->box_ = box;
   guide->net_ = owner->getId();
   guide->guide_next_ = owner->guides_;
@@ -206,6 +229,7 @@ void dbGuide::destroy(dbGuide* guide)
     block->_journal->pushParam(_guide->box_.xMax());
     block->_journal->pushParam(_guide->box_.yMax());
     block->_journal->pushParam(_guide->layer_);
+    block->_journal->pushParam(_guide->via_layer_);
     block->_journal->endAction();
   }
 
diff --git a/src/odb/src/db/dbGuide.h b/src/odb/src/db/dbGuide.h
index 2c3b4dfdd52..16bc1dd4558 100644
--- a/src/odb/src/db/dbGuide.h
+++ b/src/odb/src/db/dbGuide.h
@@ -61,6 +61,7 @@ class _dbGuide : public _dbObject
   dbId<_dbNet> net_;
   Rect box_;
   dbId<_dbTechLayer> layer_;
+  dbId<_dbTechLayer> via_layer_;
   dbId<_dbGuide> guide_next_;
 };
 dbIStream& operator>>(dbIStream& stream, _dbGuide& obj);
diff --git a/src/odb/src/db/dbJournal.cpp b/src/odb/src/db/dbJournal.cpp
index b5260b6c6fa..a38808e8831 100644
--- a/src/odb/src/db/dbJournal.cpp
+++ b/src/odb/src/db/dbJournal.cpp
@@ -1519,15 +1519,19 @@ void dbJournal::undo_deleteObject()
       int x_max;
       int y_max;
       uint layer_id;
+      uint via_layer_id;
       _log.pop(net_id);
       _log.pop(x_min);
       _log.pop(y_min);
       _log.pop(x_max);
       _log.pop(y_max);
       _log.pop(layer_id);
+      _log.pop(via_layer_id);
       auto net = dbNet::getNet(_block, net_id);
       auto layer = dbTechLayer::getTechLayer(_block->getTech(), layer_id);
-      dbGuide::create(net, layer, {x_min, y_min, x_max, y_max});
+      auto via_layer
+          = dbTechLayer::getTechLayer(_block->getTech(), via_layer_id);
+      dbGuide::create(net, layer, via_layer, {x_min, y_min, x_max, y_max});
       break;
     }
     case dbInstObj: {
diff --git a/src/odb/test/cpp/TestGuide.cpp b/src/odb/test/cpp/TestGuide.cpp
index 6f61b11fb70..b5391ba9a61 100644
--- a/src/odb/test/cpp/TestGuide.cpp
+++ b/src/odb/test/cpp/TestGuide.cpp
@@ -17,8 +17,8 @@ BOOST_AUTO_TEST_CASE(test_default)
   auto block = db->getChip()->getBlock();
   auto layer = tech->findLayer("L1");
   auto net = dbNet::create(block, "n1");
-  dbGuide::create(net, layer, {0, 0, 100, 100});
-  dbGuide::create(net, layer, {0, 100, 100, 200});
+  dbGuide::create(net, layer, layer, {0, 0, 100, 100});
+  dbGuide::create(net, layer, layer, {0, 100, 100, 200});
   net->getGuides().reverse();
   BOOST_TEST(net->getGuides().size() == 2);
   dbGuide* guide = (dbGuide*) *net->getGuides().begin();
@@ -37,9 +37,9 @@ BOOST_AUTO_TEST_CASE(test_clear_guides)
   auto block = db->getChip()->getBlock();
   auto layer = tech->findLayer("L1");
   auto net = dbNet::create(block, "n1");
-  dbGuide::create(net, layer, {0, 100, 100, 200});
-  dbGuide::create(net, layer, {0, 100, 100, 200});
-  dbGuide::create(net, layer, {0, 100, 100, 200});
+  dbGuide::create(net, layer, layer, {0, 100, 100, 200});
+  dbGuide::create(net, layer, layer, {0, 100, 100, 200});
+  dbGuide::create(net, layer, layer, {0, 100, 100, 200});
   BOOST_TEST(net->getGuides().size() == 3);
   net->clearGuides();
   BOOST_TEST(net->getGuides().size() == 0);
diff --git a/src/odb/test/cpp/TestJournal.cpp b/src/odb/test/cpp/TestJournal.cpp
index aea5a0c7373..a36f59e93bd 100644
--- a/src/odb/test/cpp/TestJournal.cpp
+++ b/src/odb/test/cpp/TestJournal.cpp
@@ -90,7 +90,7 @@ BOOST_FIXTURE_TEST_CASE(test_undo_net_destroy_guides, F_DEFAULT)
   auto net = dbNet::create(block, "n");
   auto l1 = db->getTech()->findLayer("L1");
   const Rect box{0, 0, 100, 100};
-  dbGuide::create(net, l1, box);
+  dbGuide::create(net, l1, l1, box);
 
   in_eco([&]() { dbNet::destroy(net); });
 
@@ -98,6 +98,7 @@ BOOST_FIXTURE_TEST_CASE(test_undo_net_destroy_guides, F_DEFAULT)
   const auto guide = *net->getGuides().begin();
   BOOST_TEST(guide->getLayer() == l1);
   BOOST_TEST(guide->getBox() == box);
+  BOOST_TEST(guide->getViaLayer() == l1);
 }
 
 BOOST_FIXTURE_TEST_CASE(test_undo_guide_create, F_DEFAULT)
@@ -106,7 +107,7 @@ BOOST_FIXTURE_TEST_CASE(test_undo_guide_create, F_DEFAULT)
   auto l1 = db->getTech()->findLayer("L1");
   const Rect box{0, 0, 100, 100};
 
-  in_eco([&]() { dbGuide::create(net, l1, box); });
+  in_eco([&]() { dbGuide::create(net, l1, l1, box); });
 
   BOOST_TEST(net->getGuides().size() == 0);
 }