diff --git a/examples/exp_configs/non_rl/aimsun_template.py b/examples/exp_configs/non_rl/aimsun_template.py
index 7ab4fd13b..69181ac28 100644
--- a/examples/exp_configs/non_rl/aimsun_template.py
+++ b/examples/exp_configs/non_rl/aimsun_template.py
@@ -33,7 +33,6 @@
     sim=AimsunParams(
         sim_step=0.1,
         render=True,
-        emission_path='data',
         replication_name="Replication 930",
         centroid_config_name="Centroid Configuration 910"
     ),
diff --git a/examples/exp_configs/non_rl/figure_eight.py b/examples/exp_configs/non_rl/figure_eight.py
index 13444261a..37c155cff 100755
--- a/examples/exp_configs/non_rl/figure_eight.py
+++ b/examples/exp_configs/non_rl/figure_eight.py
@@ -15,7 +15,9 @@
 vehicles = VehicleParams()
 vehicles.add(
     veh_id="idm",
-    acceleration_controller=(IDMController, {}),
+    acceleration_controller=(IDMController, {
+        "noise": 0.1,
+    }),
     lane_change_controller=(StaticLaneChanger, {}),
     routing_controller=(ContinuousRouter, {}),
     car_following_params=SumoCarFollowingParams(
diff --git a/examples/exp_configs/non_rl/i210_subnetwork.py b/examples/exp_configs/non_rl/i210_subnetwork.py
new file mode 100644
index 000000000..873028304
--- /dev/null
+++ b/examples/exp_configs/non_rl/i210_subnetwork.py
@@ -0,0 +1,55 @@
+"""Runs a simulation of the I-210 subnetwork."""
+from flow.core.params import AimsunParams, EnvParams, NetParams
+from flow.core.params import VehicleParams
+from flow.core.params import InFlows
+import flow.config as config
+from flow.envs import TestEnv
+from flow.networks import Network
+import os
+
+
+# no vehicles in the network
+vehicles = VehicleParams()
+
+# path to the imported Aimsun template
+template_path = os.path.join(
+    config.PROJECT_PATH, "examples/prebuilt/aimsun/i_210_sub_merge_020620.ang")
+
+
+flow_params = dict(
+    # name of the experiment
+    exp_tag='I-210_subnetwork',
+
+    # name of the flow environment the experiment is running on
+    env_name=TestEnv,
+
+    # name of the network class the experiment is running on
+    network=Network,
+
+    # simulator that is used by the experiment
+    simulator='aimsun',
+
+    # Aimsun-related parameters
+    sim=AimsunParams(
+        sim_step=0.1,  # FIXME: 0.8?
+        render=True,
+        replication_name="Replication 930",  # FIXME
+        centroid_config_name="Centroid Configuration 910"  # FIXME
+    ),
+
+    # environment related parameters (see flow.core.params.EnvParams)
+    env=EnvParams(
+        horizon=3000,  # FIXME
+    ),
+
+    # network-related parameters (see flow.core.params.NetParams and the
+    # network's documentation or ADDITIONAL_NET_PARAMS component)
+    net=NetParams(
+        inflows=InFlows(),
+        template=template_path
+    ),
+
+    # vehicles to be placed in the network at the start of a rollout (see
+    # flow.core.params.VehicleParams)
+    veh=vehicles,
+)
diff --git a/examples/exp_configs/non_rl/merge.py b/examples/exp_configs/non_rl/merge.py
index 2a1ff0455..5d37b44fc 100644
--- a/examples/exp_configs/non_rl/merge.py
+++ b/examples/exp_configs/non_rl/merge.py
@@ -57,7 +57,6 @@
     # sumo-related parameters (see flow.core.params.SumoParams)
     sim=SumoParams(
         render=True,
-        emission_path="./data/",
         sim_step=0.2,
         restart_instance=False,
     ),
diff --git a/examples/exp_configs/non_rl/ring.py b/examples/exp_configs/non_rl/ring.py
index bffbdf3ba..1dfd28e99 100755
--- a/examples/exp_configs/non_rl/ring.py
+++ b/examples/exp_configs/non_rl/ring.py
@@ -6,6 +6,7 @@
 from flow.controllers import IDMController, ContinuousRouter
 from flow.core.params import SumoParams, EnvParams, InitialConfig, NetParams
 from flow.core.params import VehicleParams
+from flow.core.params import SumoCarFollowingParams
 from flow.envs.ring.accel import AccelEnv, ADDITIONAL_ENV_PARAMS
 from flow.networks.ring import RingNetwork, ADDITIONAL_NET_PARAMS
 
@@ -15,6 +16,9 @@
     veh_id="idm",
     acceleration_controller=(IDMController, {}),
     routing_controller=(ContinuousRouter, {}),
+    car_following_params=SumoCarFollowingParams(
+        min_gap=0,
+    ),
     num_vehicles=22)
 
 
diff --git a/examples/exp_configs/rl/multiagent/multiagent_ring.py b/examples/exp_configs/rl/multiagent/multiagent_ring.py
index e7688c87d..8e33cc444 100644
--- a/examples/exp_configs/rl/multiagent/multiagent_ring.py
+++ b/examples/exp_configs/rl/multiagent/multiagent_ring.py
@@ -12,6 +12,7 @@
 from flow.core.params import NetParams
 from flow.core.params import SumoParams
 from flow.core.params import VehicleParams
+from flow.core.params import SumoCarFollowingParams
 from flow.envs.multiagent import MultiWaveAttenuationPOEnv
 from flow.networks import MultiRingNetwork
 from flow.utils.registry import make_create_env
@@ -35,6 +36,9 @@
         acceleration_controller=(IDMController, {
             'noise': 0.2
         }),
+        car_following_params=SumoCarFollowingParams(
+            min_gap=0
+        ),
         routing_controller=(ContinuousRouter, {}),
         num_vehicles=21)
     vehicles.add(
diff --git a/examples/prebuilt/aimsun/i_210_sub_merge_020620.ang b/examples/prebuilt/aimsun/i_210_sub_merge_020620.ang
new file mode 100644
index 000000000..0b0135d5f
Binary files /dev/null and b/examples/prebuilt/aimsun/i_210_sub_merge_020620.ang differ
diff --git a/examples/simulate.py b/examples/simulate.py
index 04967b830..a46466bde 100644
--- a/examples/simulate.py
+++ b/examples/simulate.py
@@ -6,6 +6,7 @@
 import argparse
 import sys
 from flow.core.experiment import Experiment
+from flow.core.params import AimsunParams
 
 
 def parse_args(args):
@@ -60,6 +61,12 @@ def parse_args(args):
     flow_params['sim'].render = not flags.no_render
     flow_params['simulator'] = 'aimsun' if flags.aimsun else 'traci'
 
+    # If Aimsun is being called, replace SumoParams with AimsunParams.
+    if flags.aimsun:
+        sim_params = AimsunParams()
+        sim_params.__dict__.update(flow_params['sim'].__dict__)
+        flow_params['sim'] = sim_params
+
     # specify an emission path if they are meant to be generated
     if flags.gen_emission:
         flow_params['sim'].emission_path = "./data"
diff --git a/flow/core/kernel/network/aimsun.py b/flow/core/kernel/network/aimsun.py
index 0378d45a9..f5d9b599b 100644
--- a/flow/core/kernel/network/aimsun.py
+++ b/flow/core/kernel/network/aimsun.py
@@ -258,11 +258,13 @@ def update(self, reset):
 
     def close(self):
         """See parent class."""
-        # delete the json file that was used to read the network data
-        cur_dir = os.path.join(config.PROJECT_PATH,
-                               'flow/core/kernel/network')
-        os.remove(os.path.join(cur_dir, 'data_%s.json' % self.sim_params.port))
-        os.remove('%s_%s' % (self.network.net_params.template, self.sim_params.port))
+        try:
+            # delete the json file that was used to read the network data
+            cur_dir = os.path.join(config.PROJECT_PATH, 'flow/core/kernel/network')
+            os.remove(os.path.join(cur_dir, 'data_%s.json' % self.sim_params.port))
+            os.remove('%s_%s' % (self.network.net_params.template, self.sim_params.port))
+        except FileNotFoundError:
+            pass
 
     ###########################################################################
     #                        State acquisition methods                        #
diff --git a/flow/core/kernel/simulation/aimsun.py b/flow/core/kernel/simulation/aimsun.py
index 91b4c4abd..f24428290 100644
--- a/flow/core/kernel/simulation/aimsun.py
+++ b/flow/core/kernel/simulation/aimsun.py
@@ -1,8 +1,11 @@
 """Script containing the base simulation kernel class."""
-from flow.core.kernel.simulation.base import KernelSimulation
-from flow.utils.aimsun.api import FlowAimsunAPI
+import os
+import signal
 import os.path as osp
 import csv
+
+from flow.core.kernel.simulation.base import KernelSimulation
+from flow.utils.aimsun.api import FlowAimsunAPI
 from flow.core.util import ensure_dir
 
 
@@ -126,6 +129,10 @@ def close(self):
         try:
             self.kernel_api.stop_simulation()
             self.master_kernel.network.aimsun_proc.kill()
+
+            # Weird bug that I don't understand. This closes Aimsun's window.
+            pid = self.master_kernel.network.aimsun_proc.pid + 1
+            os.kill(pid, signal.SIGTERM)
         except OSError:
             # in case no simulation originally existed (used by the visualizer)
             pass
diff --git a/flow/core/kernel/vehicle/aimsun.py b/flow/core/kernel/vehicle/aimsun.py
index 9e791a10d..5529225dc 100644
--- a/flow/core/kernel/vehicle/aimsun.py
+++ b/flow/core/kernel/vehicle/aimsun.py
@@ -47,11 +47,6 @@ def __init__(self,
         # Ordered dictionary used to keep neural net inputs in order
         self.__vehicles = collections.OrderedDict()
 
-        # total number of vehicles in the network
-        self.num_vehicles = 0
-        # number of rl vehicles in the network
-        self.num_rl_vehicles = 0
-
         # contains the parameters associated with each type of vehicle
         self.type_parameters = {}
 
@@ -110,8 +105,6 @@ def initialize(self, vehicles):
             individual vehicles and their initial speeds
         """
         self.type_parameters = vehicles.type_parameters
-        self.num_vehicles = 0
-        self.num_rl_vehicles = 0
 
         self.__vehicles.clear()
         for typ in vehicles.initial:
@@ -121,9 +114,6 @@ def initialize(self, vehicles):
                 self.__vehicles[veh_id]['type'] = typ['veh_id']
                 self.__vehicles[veh_id]['type_name'] = typ['veh_id']  # FIXME
                 self.__vehicles[veh_id]['initial_speed'] = typ['initial_speed']
-                self.num_vehicles += 1
-                if typ['acceleration_controller'][0] == RLController:
-                    self.num_rl_vehicles += 1
 
         # for tracked_type in self.tracked_vehicle_types:
         #     self.num_type[tracked_type] = 0
@@ -174,6 +164,12 @@ def update(self, reset):
         added_vehicles = self.kernel_api.get_entered_ids()
         exited_vehicles = self.kernel_api.get_exited_ids()
 
+        # updated the list of departed and arrived vehicles
+        self._num_departed.append(len(added_vehicles))
+        self._num_arrived.append(len(exited_vehicles))
+        self._departed_ids.append(added_vehicles)
+        self._arrived_ids.append(exited_vehicles)
+
         # add the new vehicles if they should be tracked
         for aimsun_id in added_vehicles:
             veh_type = self.kernel_api.get_vehicle_type_name(aimsun_id)
@@ -351,7 +347,6 @@ def _add_departed(self, aimsun_id):
             # add the vehicle's id to the list of vehicle ids
             if accel_controller[0] == RLController:
                 self.__rl_ids.append(veh_id)
-                self.num_rl_vehicles += 1
             else:
                 self.__human_ids.append(veh_id)
                 if accel_controller[0] != SimCarFollowingController:
@@ -369,7 +364,6 @@ def _add_departed(self, aimsun_id):
 
     def add(self, veh_id, type_id, edge, pos, lane, speed):
         """See parent class."""
-        self.num_vehicles += 1
         self.__ids.append(veh_id)
         self.__vehicles[veh_id] = {}
         self.__vehicles[veh_id]["type_name"] = type_id
@@ -414,7 +408,6 @@ def remove(self, aimsun_id):
         del self._id_aimsun2flow[aimsun_id]
         del self._id_flow2aimsun[veh_id]
         self.__ids.remove(veh_id)
-        self.num_vehicles -= 1
 
         # remove it from all other ids (if it is there)
         if veh_id in self.__human_ids:
@@ -426,7 +419,6 @@ def remove(self, aimsun_id):
         elif veh_id in self.__rl_ids:
             # FIXME should be else
             self.__rl_ids.remove(veh_id)
-            self.num_rl_vehicles -= 1
 
         # make sure that the rl ids remain sorted
         self.__rl_ids.sort()
@@ -802,3 +794,11 @@ def get_lane_followers_speed(self, veh_id, error=None):
     def get_lane_leaders_speed(self, veh_id, error=None):
         """See parent class."""
         raise NotImplementedError
+
+    @property
+    def num_vehicles(self):
+        return len(self.__ids)
+
+    @property
+    def num_rl_vehicles(self):
+        return len(self.__rl_ids)
diff --git a/flow/envs/base.py b/flow/envs/base.py
index 7749ffea5..0166b6ff7 100644
--- a/flow/envs/base.py
+++ b/flow/envs/base.py
@@ -392,8 +392,10 @@ def step(self, rl_actions):
 
         # test if the environment should terminate due to a collision or the
         # time horizon being met
-        done = (self.time_counter >= self.env_params.warmup_steps +
-                self.env_params.horizon)  # or crash
+        current_time = self.time_counter / self.env_params.sims_per_step
+        max_time = self.env_params.warmup_steps + self.env_params.horizon
+
+        done = (current_time >= max_time)  # or crash
 
         # compute the info for each agent
         infos = {}
@@ -478,8 +480,7 @@ def reset(self):
 
         # reintroduce the initial vehicles to the network
         for veh_id in self.initial_ids:
-            type_id, edge, lane_index, pos, speed = \
-                self.initial_state[veh_id]
+            type_id, edge, lane_index, pos, speed = self.initial_state[veh_id]
 
             try:
                 self.k.vehicle.add(
diff --git a/flow/networks/ring.py b/flow/networks/ring.py
index de4d17503..ceef22a78 100755
--- a/flow/networks/ring.py
+++ b/flow/networks/ring.py
@@ -37,7 +37,7 @@ class RingNetwork(Network):
     >>> from flow.core.params import NetParams
     >>> from flow.core.params import VehicleParams
     >>> from flow.core.params import InitialConfig
-    >>> from flow.scenarios import RingNetwork
+    >>> from flow.networks import RingNetwork
     >>>
     >>> network = RingNetwork(
     >>>     name='ring_road',
diff --git a/flow/utils/aimsun/generate.py b/flow/utils/aimsun/generate.py
index 25ed213b0..b8f3cd379 100644
--- a/flow/utils/aimsun/generate.py
+++ b/flow/utils/aimsun/generate.py
@@ -33,6 +33,7 @@
 port_string = sys.argv[1]
 model.setAuthor(port_string)
 
+
 def generate_net(nodes,
                  edges,
                  connections,