SLIF App

Updated on Mar 4, 2026

When running this app, VBOX Touch can efficiently validate Speed Limit Information Function (SLIF) and Intelligent Speed Assist (ISA) systems. The app logs distance data and sign recognition inputs (OK/NOK), and calculates the True Positive Distance (TP_D - percentage of total distance where the displayed speed limit matches the road signs).

Key features include:

  • Real-time compliance monitoring for displayed speed vs real-world signage (TP_D).
  • Driving session tracking across urban, inter-urban, and highway conditions, day or night.
  • Event logging with the SLIF Event Marker Box (RLACS348).
  • Integration with VBOX HD2 (optional) for video and data overlays.
  • CAN connectivity (DBC file needed) for broader test setups.

To use the SLIF app for VBOX Touch,  you need a VBOX Touch for the primary input and a Video Data Logger to capture the data from outside and inside the vehicle. The app works with a simple button box. If the speed limit on the dashboard does not match the speed limit on the road, press the Black button on the button box to trigger NOK distance. When the speed limit on the dashboard matches the speed limit on the road, press the Black button again to trigger OK distance. 

LandingPage
SLIF_Results_button
Press the Results button to open the Results pages. 
SLIF_Results_button
Press the Results button to open the Results pages. 
SLIF_Settings_button
Press the Settings button to open the app Settings and Diagnostics screens. 
SLIF_Settings_button
Press the Settings button to open the app Settings and Diagnostics screens. 
SLIF_NewTest_button

Press the New Test button to start a new test. 

SLIF_ContinueTest_button

Press the Continue Test button to continue the previous test. 

The test display will provide you with the test data and an easy to read OK/NOK state. 

OKState

Stop Test

SLIF_StopTest_button
Click on the STOP TEST button when a test is running to stop the test. 
SLIF_StopTest_button
Click on the STOP TEST button when a test is running to stop the test. 

The test must include both driving in daylight and in darkness conditions, where at least 15% of the total distance is done in darkness. By changing the light condition setting in the SLIF app, the app will record the distance and percentage of the total distance that is performed in darkness.   

SLIF_LightMode_button_Daylight
SLIF_LightMode_button
Click on the Light Mode button to toggle between daylight and darkness conditions.  
SLIF_LightMode_button_Daylight
SLIF_LightMode_button
Click on the Light Mode button to toggle between daylight and darkness conditions.  
SLIF_Display_Daylight
OKState
SLIF_Display_Daylight
OKState
Daylight Conditions
Darkness Conditions
SLIF_TotalDistance
This area will display the total distance covered in the test so far. 
SLIF_TotalDistance
This area will display the total distance covered in the test so far. 
SLIF_RoadType

You can select the Road Type you are performing the test on: 

  • Urban
  • Inter-Urban
  • Highway

The selected Road Type button will become coloured depending on the triggered state (see State section below), the unselected Road Type buttons will remain grey. 

SLIF_RoadType

You can select the Road Type you are performing the test on: 

  • Urban
  • Inter-Urban
  • Highway

The selected Road Type button will become coloured depending on the triggered state (see State section below), the unselected Road Type buttons will remain grey. 

SLIF_RoadInfo
This area will display the Road Distance, Distance NOK and TP_D for the selected Road Type.  
SLIF_RoadInfo
This area will display the Road Distance, Distance NOK and TP_D for the selected Road Type.  

 Depending on the results of the test, the following areas on the Test Display will change to indicate the state:

OK State
NOK State
OKState
NOKState
OKState
NOKState

Depending on the set LED behaviour in the settings, the LEDs above the display will do one of the following:

LED Mode - Persist
The LEDs will illuminate green when the state is OK and red when the state is Not OK.

LED Mode - Flash 
The LEDs will flash green when the state is OK and flash red when the state is NOK.

LED Brightness - OFF
The LEDs are turned off and will not illuminate. 

The frame around the distances and TP_D for the road type will be green when the state is OK and red when the state is Not OK.

The colour of the selected  Road Type button will be green when the state is OK and red when the state is Not OK.

When you press the white button on the button box, the Test Display will change the frame and button colour to orange and the LEDs will flash red to indicate and event being marked. Press the button again to stop the event marking and return to OK/NOK state. 

EventState

The results will update live when a test is running.

The colour of the frame around a result will indicate if it is OK or NOK.  

Results Page 1
Results Page 2
Results1
SLIF_Results2
Results1
SLIF_Results2

Results Page 1 will automatically be displayed when you press the STOP TEST button.

This page will provide a summary of the Distance, TP_D, TP_D Variance, Darkness % and Road %

Use the arrow buttons in the top right corner to navigate to Results Page 2.

Results Page 2 displays an overview of the performed test with the Distance, TP_D, TP_D Variance, Darkness % and Road % for each Road Type.

When you press the Settings button on the landing page, the Settings and Diagnostics area will be displayed. The Settings page will automatically be displayed. 

SLIF_Settings

These settings control the brightness of the display and the LEDs. The higher the number the brighter the Display/LED. 

Display

  • 1
  • 2
  • 3
  • 4
  • 5

LEDs

  • Off
  • 1
  • 2
  • 3
  • 4
  • 5

You can change the LED Mode for the application. You can choose between the following: 

  • Persist
    The LEDs will illuminate in the state colour when the state changes and will stay illuminated until the state changes again. 
  • Flash
    The LEDs  will flash in the state colour when the state changes and will turn off until the state changes again. 

You can adjust the number of GNSS Leap Seconds to apply. 

To access the Diagnostics screen, press Diagnostics in the bottom right corner while in the Settings.  

SLIF_Diagnostics

This area provides information about the number of satellites being tracked and the constellations they are in. 

COLDSTART

Press the coldstart button to perform a GNSS coldstart.

A GNSS coldstart may be required when: 

  • The GNSS engine has locked up.
  • The VBOX is struggling to acquire satellite lock.

A GNSS coldstart forces the GNSS engine to reset its downloaded almanac of current satellite positions.  Constellation almanacs have information about orbit data and research on active GNSS satellites in the constellation. 

This area provides information about: 

  • the serial number
  • the hardware code
  • the app version
  • the system version
  • the active .vbo file 

Connect the equipment as illustrated below: 

SLIF_HardwareConnections
SLIF_NewTest
  1. Press the New Test button.
  2. Select the Road Type.
  3. The test will begin.
  4. Press a Road Type button any time to change the road type during the test.
SLIF_operation

Tap inside the border area on the Test Display or use the Black button on the button box to toggle between OK or NOK.

Press the White button on the button box to mark events. Press it again to stop the event trigger.

The test should be performed over a distance of 400 km. It may, however, be terminated earlier if the test distance exceeds 300 km and the performance 'TP_D' varied between ± 5.0 % during the final 50 km of the route when calculated on a continuous basis. 

Conditions for early finish are monitored from 250 km. 

You will get the option to end the test early or continue it. 

SLIF_EarlyFinish

You can stop the test at any time by pressing the STOP TEST button.

When a test has been stopped, you can continue it by pressing the Continue Test button on the Landing page. 

Load the files from both the VBOX Touch and the Video Data Logger into VBOX Test Suite for post-test analysis. 

SLIF_TestSuiteAnalysis