diff --git a/README.md b/README.md
index c9b834b..bdd6bb8 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,9 @@ a folder that will serve as configuration directory and fill in the
 information. The directory will be used as volume during container 
 operation.
 
+## start database
+`docker run --name pitstops_db -e MYSQL_ROOT_PASSWORD=$SOMESECUREPASSWORD$ -e MYSQL_DATABASE=pitstops -d mysql:latest`
+
 ## run in development
 
 Include the development version of the code as volume, so the app gets
@@ -22,3 +25,4 @@ debugging during development.
 
 ## run in production
 `docker run --name pitstops -d -v /data/pitstops/:/data -v /configs/pitstops/:/app/config -p 80:5000 rollerverbrauch`
+
diff --git a/app/rollerverbrauch/__init__.py b/app/rollerverbrauch/__init__.py
index 0465b5d..3581461 100644
--- a/app/rollerverbrauch/__init__.py
+++ b/app/rollerverbrauch/__init__.py
@@ -21,11 +21,7 @@ app.config.from_object(__name__)
 db = SQLAlchemy(app)
 mail = Mail(app)
 
-from rollerverbrauch.tools import \
-    VehicleStats, \
-    db_log_add, \
-    db_log_delete, \
-    db_log_update
+import rollerverbrauch.tools as tools
 
 from rollerverbrauch.forms import \
     CreatePitstopForm, \
@@ -58,8 +54,8 @@ def user_registered_sighandler(app, user, confirm_token):
     db.session.add(new_vehicle)
     user.vehicles.append(new_vehicle)
     db.session.commit()
-    db_log_add(user)
-    db_log_add(new_vehicle)
+    tools.db_log_add(user)
+    tools.db_log_add(new_vehicle)
 
 
 @app.before_first_request
@@ -88,9 +84,11 @@ def edit_vehicle(vid):
     form = EditVehicleForm()
 
     if form.validate_on_submit():
+        if not tools.check_vehicle_name_is_unique(current_user, form.name):
+            return render_template('editVehicleForm.html', form=form)
         vehicle.name = form.name.data
         db.session.commit()
-        db_log_update(vehicle)
+        tools.db_log_update(vehicle)
         return redirect(url_for('get_account_page'))
 
     form.name.default = vehicle.name
@@ -112,7 +110,7 @@ def delete_vehicle(vid):
     if form.validate_on_submit():
         db.session.delete(vehicle)
         db.session.commit()
-        db_log_delete(vehicle)
+        tools.db_log_delete(vehicle)
         return redirect(url_for('get_account_page'))
 
     return render_template('deleteVehicleForm.html', form=form, vehicle=vehicle)
@@ -124,11 +122,14 @@ def create_vehicle():
     form = EditVehicleForm()
 
     if form.validate_on_submit():
-        new_vehicle = Vehicle(form.name.data)
+        vehicle_name = form.name.data
+        if not tools.check_vehicle_name_is_unique(current_user, form.name):
+            return render_template('createVehicleForm.html', form=form)
+        new_vehicle = Vehicle(vehicle_name)
         db.session.add(new_vehicle)
         current_user.vehicles.append(new_vehicle)
         db.session.commit()
-        db_log_add(new_vehicle)
+        tools.db_log_add(new_vehicle)
         return redirect(url_for('get_account_page'))
 
     return render_template('createVehicleForm.html', form=form)
@@ -170,7 +171,7 @@ def create_pit_stop_form(vid):
         db.session.add(new_stop)
         vehicle.pitstops.append(new_stop)
         db.session.commit()
-        db_log_add(new_stop)
+        tools.db_log_add(new_stop)
         return redirect(url_for('get_pit_stops', _anchor= 'v' + str(vehicle.id)))
 
     form.odometer.default = last_pitstop.odometer
@@ -214,5 +215,5 @@ def get_account_page():
 def get_statistics():
     stats = []
     for vehicle in current_user.vehicles:
-        stats.append(VehicleStats(vehicle))
+        stats.append(tools.VehicleStats(vehicle))
     return render_template('statistics.html', data=stats)
diff --git a/app/rollerverbrauch/entities.py b/app/rollerverbrauch/entities.py
index f89069b..64d456b 100644
--- a/app/rollerverbrauch/entities.py
+++ b/app/rollerverbrauch/entities.py
@@ -40,10 +40,11 @@ class User(db.Model, UserMixin):
 class Vehicle(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     owner_id = db.Column(db.Integer, db.ForeignKey('user.id'))
-    name = db.Column(db.String(255), unique=True)
+    name = db.Column(db.String(255))
     pitstops = db.relationship(
         'Pitstop'
     )
+    __table_args__ = (db.UniqueConstraint('owner_id', 'name', name='_owner_name_uniq'),)
 
     def __init__(self, name):
         self.name = name
diff --git a/app/rollerverbrauch/tools.py b/app/rollerverbrauch/tools.py
index ca68794..3099d76 100644
--- a/app/rollerverbrauch/tools.py
+++ b/app/rollerverbrauch/tools.py
@@ -47,3 +47,21 @@ def db_log_delete(entity):
 
 def db_log_update(entity):
     logging.info('db_update: %s' % str(entity))
+
+
+def check_vehicle_name_is_unique(current_user, name_field):
+    """
+    Checks if the vehicle name given in the name_field is unique for the vehicles of the current user. An error is added
+    to the field it the name is not unique.
+
+    :param current_user: the user currently logged in
+    :param name_field: the form field to enter the name to
+    :return: True if the name is unique, False otherwise.
+    """
+    vehicle_name = name_field.data
+    for vehicle in current_user.vehicles:
+        if vehicle.name == vehicle_name:
+            name_field.default = vehicle_name
+            name_field.errors.append('Vehicle "%s" already exists.' % vehicle_name)
+            return False
+    return True
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