<xs:complexType name="TrafficAreaStructureAttributeType">
    <xs:complexContent>
      <xs:extension base="uro:TrafficAreaAttributeType">
        <xs:sequence>
          <xs:element name="numberOfLanes" minOccurs="0" type="xs:integer"/>
        </xs:sequence>
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>