<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
  <ul class="navbar-nav mr-auto">
    <li class="nav-item active">
      <a class="nav-link" href="/">Home <span class="sr-only">(current)</span></a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/vehicles">Vehicles</a>
    </li>
    <li class="nav-item dropdown">
      <a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#!" role="button" aria-haspopup="true" aria-expanded="false">Forms</a>
      <div class="dropdown-menu">
        <a class="dropdown-item" href="forms/index.php">Form 1</a>
        <a class="dropdown-item" href="">Form 2</a>
      </div>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/about">About</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/news">News</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="/join">Join Us</a>
    </li>
  </ul>
</nav>