This Function shall be capable of providing the following facilities:<br/><br/>(1) The ability to receive both the current recommended speeds and headways and the legal speed limits for display to the Driver of the Host Vehicle.<br/>(2) A HMI that shall be able to display both speed limits, except when either there is no recommended speed limit, or it is greater than the legal speed limit.<br/>(3) If there is no recommended speed limit, or it is greater that the legal speed limit, the HMI shall have the ability to display the legal speed limit with a warning that there is no recommended speed limit.<br/>(4) If the speed of the Host Vehicle exceeds either the recommended speed or the legal speed limit, then the HMI shall display a warning message to the Driver.<br/>(5) The HMI shall only display the headway with the recommended speed limit.<br/>(6) When any changes are made to the recommended speed and headway, the HMI shall be able to provide an indication of the reason for the change.<br/>(7) The HMI shall also have the ability to display a warning when the Host Vehicle is being driven in an unsafe manor, i.e. poor safety behaviour due to excessive speed, or maintaining less than the minimum headway.<br/>(8) The HMI shall be able to continuously update the display to provide the Driver with the speed and headway for the Host Vehicle's current and expected locations within the road network and to show or remove any unsafe driving warnings.<br/>(9) If for any reason the HMI does not receive any inputs, it shall have the ability to show a "system not working" indication.<br/>
(a) continuously monitor for receipt of any of the input data flows;<br/>(b) whenever the road information for display data flow is received in (a), display its contents including the legal speed limit and the part of the road network (inter-urban or urban) that the Host Vehicle is using to the Driver through the HMI using the current road information data flow;<br/>(c) whenever the current recommended speed and headway data flow is received in (a), display its contents (including the reasons for changes) to the Driver through the HMI using the current speed limits and headways output data flow;<br/>(d) in (c) continue to display the recommended speed limit provided that it is less than the legal speed limit for the current and expected next road segments;<br/>(e) if no recommended speed limit is received in (a), then only display the current legal speed limit received in (b) and output to the Driver through the HMI with it an advisory message saying that there is no recommended speed limit;<br/>(f) if the recommended speed limit received in (c) exceeds the legal speed limit received in (b) then only display the legal speed limit and output to the Driver through the HMI an advisory message saying that there is no recommended speed limit;<br/>(g) if no recommended or legal speed limits are received in (b) or (c) then output a message to the Driver through the HMI in the current speed limit data flow saying the speed limit service is unavailable;<br/>(h) when the roadside speed indication details data flow is received in (a) check the speed value it contains against the current legal and recommended speed limits that have been received in (b) and (c);<br/>(i) if a difference is found in (h), provide a warning of this to the Driver in the possible speed indication error data flow and also send the data from which the same warning message can be produced to either the Output Lane & Speed Messages to Inter-urban Roads function (if the inter-urban speed is being exceeded) or Output Urban Lane & Speed Commands function (if the urban speed is being exceeded) depending on whether the Vehicle is in the inter-urban or urban part of the road network;<br/>(j) continue to send the output in (i) for as long as the difference persists and stop output of the possible speed indication error data flow when it does not;<br/>(k) the output of the possible speed indication error data flow should only be made if a recommended or legal speed limit has been received in (b) or (c), i.e. the output must not be sent if there is no data with which to make a comparison;<br/>(l) when the vehicle speed data flow is received in (a), check it against the legal speed limit received in (b) and the recommended speed received in (c) and display a warning to the Driver if either is being exceeded by the Vehicle in the recommended speed or legal speed limit exceeded data flow;<br/>(m) if either of the data flows in (l) is sent then determine in which part of the road network (inter-urban or urban) the Vehicle is located and send whichever is appropriate of the inter-urban speed being exceeded or urban speed being exceeded data flows to the Output Lane & Speed Commands to Inter-urban Roads or Output Lane & Speed Commands to Urban Roads functions respectively;<br/>(n) the output of all speed limit information must be made in a standard way;<br/>(o) whenever the fused road and traffic conditions data flow is received in (a), display its contents to the Driver through the HMI using the current road and traffic conditions data flow;<br/>(p) whenever the safety behaviour status for display data flow is received in (a), display the warning that it contains to the Driver through the HMI using the safety behaviour warning data flow, for as long as the warning is received, it being removed when it ceases to be present;<br/>(q) if none of the data flows is received in (a) for a period of time, the display shall show a "system not working" indication to the Driver through the HMI.<br/>
