diff --git a/reinforcement_learning/multi_agent_training.py b/reinforcement_learning/multi_agent_training.py
index 9c78a72b6dd3515de9f34ab2c24f5ac76cb7a34b..fd85fdc8e77530b0223b4f71a952887b47eb762f 100755
--- a/reinforcement_learning/multi_agent_training.py
+++ b/reinforcement_learning/multi_agent_training.py
@@ -1,23 +1,22 @@
-from datetime import datetime
 import os
 import random
 import sys
 from argparse import ArgumentParser, Namespace
+from collections import deque
+from datetime import datetime
 from pathlib import Path
 from pprint import pprint
-import psutil
-from flatland.utils.rendertools import RenderTool
-from torch.utils.tensorboard import SummaryWriter
-import numpy as np
-import torch
-from collections import deque
 
+import numpy as np
+import psutil
+from flatland.envs.malfunction_generators import malfunction_from_params, MalfunctionParameters
+from flatland.envs.observations import TreeObsForRailEnv
+from flatland.envs.predictions import ShortestPathPredictorForRailEnv
 from flatland.envs.rail_env import RailEnv, RailEnvActions
 from flatland.envs.rail_generators import sparse_rail_generator
 from flatland.envs.schedule_generators import sparse_schedule_generator
-from flatland.envs.observations import TreeObsForRailEnv
-from flatland.envs.malfunction_generators import malfunction_from_params, MalfunctionParameters
-from flatland.envs.predictions import ShortestPathPredictorForRailEnv
+from flatland.utils.rendertools import RenderTool
+from torch.utils.tensorboard import SummaryWriter
 
 base_dir = Path(__file__).resolve().parent.parent
 sys.path.append(str(base_dir))
@@ -250,6 +249,7 @@ def train_agent(train_params, train_env_params, eval_env_params, obs_params):
         # Run episode
         for step in range(max_steps - 1):
             inference_timer.start()
+            policy.start_step()
             for agent in train_env.get_agent_handles():
                 if info['action_required'][agent]:
                     update_values[agent] = True
@@ -264,6 +264,7 @@ def train_agent(train_params, train_env_params, eval_env_params, obs_params):
                     update_values[agent] = False
                     action = 0
                 action_dict.update({agent: action})
+            policy.end_step()
             inference_timer.end()
 
             # Environment step
@@ -285,7 +286,8 @@ def train_agent(train_params, train_env_params, eval_env_params, obs_params):
                 if update_values[agent] or done['__all__']:
                     # Only learn from timesteps where somethings happened
                     learn_timer.start()
-                    policy.step(agent_prev_obs[agent], agent_prev_action[agent], all_rewards[agent], agent_obs[agent], done[agent])
+                    policy.step(agent_prev_obs[agent], agent_prev_action[agent], all_rewards[agent], agent_obs[agent],
+                                done[agent])
                     learn_timer.end()
 
                     agent_prev_obs[agent] = agent_obs[agent].copy()
@@ -434,6 +436,7 @@ def eval_policy(env, tree_observation, policy, train_params, obs_params):
         final_step = 0
 
         for step in range(max_steps - 1):
+            policy.start_step()
             for agent in env.get_agent_handles():
                 if tree_observation.check_is_observation_valid(agent_obs[agent]):
                     agent_obs[agent] = tree_observation.get_normalized_observation(obs[agent], tree_depth=tree_depth,
@@ -444,7 +447,7 @@ def eval_policy(env, tree_observation, policy, train_params, obs_params):
                     if tree_observation.check_is_observation_valid(agent_obs[agent]):
                         action = policy.act(agent_obs[agent], eps=0.0)
                 action_dict.update({agent: action})
-
+            policy.end_step()
             obs, all_rewards, done, info = env.step(action_dict)
 
             for agent in env.get_agent_handles():
@@ -495,7 +498,8 @@ if __name__ == "__main__":
     parser.add_argument("--num_threads", help="number of threads PyTorch can use", default=1, type=int)
     parser.add_argument("--render", help="render 1 episode in 100", action='store_true')
     parser.add_argument("--load_policy", help="policy filename (reference) to load", default="", type=str)
-    parser.add_argument("--use_fast_tree_observation", help="use FastTreeObs instead of stock TreeObs", action='store_true')
+    parser.add_argument("--use_fast_tree_observation", help="use FastTreeObs instead of stock TreeObs",
+                        action='store_true')
     parser.add_argument("--max_depth", help="max depth", default=2, type=int)
 
     training_params = parser.parse_args()
diff --git a/reinforcement_learning/policy.py b/reinforcement_learning/policy.py
index d5c6a3c23dacbb182dceda52617a0be12d1acf7b..b8714d1a2fd8e085d4e9e00c48c7362846e8ed87 100644
--- a/reinforcement_learning/policy.py
+++ b/reinforcement_learning/policy.py
@@ -10,3 +10,9 @@ class Policy:
 
     def load(self, filename):
         raise NotImplementedError
+
+    def start_step(self):
+        pass
+
+    def end_step(self):
+        pass
diff --git a/run.py b/run.py
index f11c94168e9ba1856665273e716361d1a2077b50..09dc04dae944bc23aaeeeb70e0789a605eb31a4a 100644
--- a/run.py
+++ b/run.py
@@ -114,6 +114,7 @@ while True:
             if not check_if_all_blocked(env=local_env):
                 time_start = time.time()
                 action_dict = {}
+                policy.start_step()
                 for agent in range(nb_agents):
                     if info['action_required'][agent]:
                         if agent in agent_last_obs and np.all(agent_last_obs[agent] == observation[agent]):
@@ -128,6 +129,7 @@ while True:
                         if USE_ACTION_CACHE:
                             agent_last_obs[agent] = observation[agent]
                             agent_last_action[agent] = action
+                policy.end_step()
                 agent_time = time.time() - time_start
                 time_taken_by_controller.append(agent_time)
 
diff --git a/utils/fast_tree_obs.py b/utils/fast_tree_obs.py
index 7e4c934212449d4e5712b01456f2bb8a7d6a1a8a..8fe6caf2535f448de561ae270ef6022d1795f12a 100755
--- a/utils/fast_tree_obs.py
+++ b/utils/fast_tree_obs.py
@@ -21,7 +21,7 @@ class FastTreeObs(ObservationBuilder):
 
     def __init__(self, max_depth):
         self.max_depth = max_depth
-        self.observation_dim = 26
+        self.observation_dim = 27
 
     def build_data(self):
         if self.env is not None: