Information contained in the Queensland MUTCD provide further guidance or requirements under the relevant Queensland MUTCD sections. A full outline of the MUTCD is available on the department's MUTCD web page.
Control of speed is an important aspect in effective and safe management of traffic. Involvement of speed-related factors in road crashes is well established and generally understood by road users.
The procedure for determining a speed limit for a speed zone in Queensland is an eight-stage process outlined in Section 3 of the department's MUTCD Part 4.
Broadly, the aim of the speed limit review process is to determine and implement a speed limit that appropriately balances the road environment, the function of the road and the safety of all road users such that speed limits are realistic, consistent and consequently encourage voluntary compliance.
In this module we will undertake a demonstration of the speed limit review technical tool following the speed limit review process described in section three of MUTCD part four.
The demonstration will follow one of the case studies outlined in appendix E of MUTCD part four.
The first sheet is the site input sheet, the user is to fill out all details in the yellow cells, as they relate to the homogenous, speed zone that is being reviewed.
Importantly, the latitude and longitude of the start and end of the speed zones are important to help identify the location of the start and end points of the speed zones being reviewed.
I have now provided all details for our demonstration site. It's important to note, that in our demonstration whilst all details will be real and factual, the purpose of this is for a demonstration only.
The next sheet is the criteria based speed limits sheet. Criteria based speed limits are described in section four of MUTCD part four. On this sheet we have the criteria based speed limits flowchart which is depicted in figure four point one of MUTCD part four. This sheet also contains the clear all and the instructions button.
Once the instruction button is pressed a pop up window opens, which depicts and describes what criteria based speed limits are, and also details the instructions for how to use this sheet.
In using this sheet, the user starts at step one and answers a series of yes or no questions to determine if any criteria based speed limits apply.
Multiple steps throughout this flowchart the user can click on the step for greater definition of the step.
[Pause] Step one is the speed zone a foreshore? For our demonstration site, the speed zone is not a foreshore, so we would click no.
You can see in selecting no [pause] step eight has been greyed out and is no longer applicable to our speed zone.
If, we were undertaking a speed limit review on a foreshore, we would click yes, and we can see here that the criteria based speed limit [pause] outcome is depicted in this cell here.
For our demonstration purposes, our site is not on a foreshore, so we would select no and move to step two.
Is the road considered a car park or access driveway?
[Pause] At any stage we can click clear all button to reset this sheet. At no stage can you click ahead and select a step if you have not completed the steps that lead into that.
I have now completed the criteria based speed limits flow chart for our demonstration site.
In the outcome you can see the criteria based speed limits do not apply, and we would move in to stages three and four of the speed limit review process.
The risk assess speed limit sheet, follows stage three of the speed limit review process which is described in section five point one of MUTCD part four.
[Pause] In the top left had corner of this sheet we have the road classification inputs, beneath that we have the crash risk rating inputs. In the middle of the sheet, we have the infrastructure risk rating inputs and on the right hand side we have our outputs, including calculations of the crash risk rating, calculation of the infrastructure risk rating, the overall road risk metric, and the risk assessed speed limit.
On the bottom right hand side we also have room for additional comments if required.
In the middle of this sheet we have an instructions button, (inaudible 3:48) estimate risk assessed speed limit button, and a clear all button.
This sheet comprises drop [sic] down menus and also cells that require inputs.
[Pause] This sheet also comprises [pause] buttons that launch pop ups, to assist the user with the inputs.
I have now provided all inputs for our demonstration site including the classification, the crashes, and type, and the infrastructure risk rating inputs.
Now, we click the estimate risk assessed speed limit button [pause] and the calculations and outputs that's depicted [sic] on the right hand side of the screen. You can see here that our demonstration site has a risk assessed speed limit of 80 kilometres an hour.
Next is the speed data speed limit stage which is stage four of the speed limit review process and described in section five point two of MUTCD part four.
On the speed data speed limit sheet we have our speed metric inputs we also have three buttons the clear all, the estimate speed data speed limit, and the instructions button.
Below that we have our outputs, and room for any additional comments if required.
[Long pause] Prior to completing this sheet, speed data must've been [sic] collected and processed as described in MUTCD part four. I have now input [sic] the speed metrics for our demonstration site, and we'll click the estimate speed data speed limit button.
[Pause] You can see that the speed data speed limit had been estimated at 90 kilometres an hour.
Next is the options selection sheet.
[Pause] Option selection is stage five of the speed limit review process and described in section six of MUTCD part four.
In the option selection sheet, we have three buttons a clear all, the undertake option selection, and instructions buttons.
We have our inputs to the option selection process, and the option selection flowchart.
There is no need to provide any inputs into this sheet simply click the undertake option selection button and all results from the previous steps will be populated and the flow chart complete.
The last sheet of the speed limit review technical tool is the engineer recommendation sheet.
[Pause] The engineer recommendation sheet follows stage six of the speed limit review process which is described in section seven of MUTCD part four.
The engineer recommendation sheet comprises three [sic] buttons, clear all, summarise findings of speed limit review technical assessments, and the instructions button.
Beneath that is a summary of all technical assessments.
[Pause] Underneath the summary, is the engineer's recommendations including the engineer's name, RPEQ number, and the date of which the speed limit review was completed.
Also, is a question [sic] to the engineer whether they accept the outcomes of the technical process or any alternate recommendations or other circumstances that they are recommending, and a justification as to why these recommendations [sic].
Beneath that, is the responsible’s [sic] officer's acceptance of the outcomes from the engineer.
The responsible officer is to input their name, position, and the date of acceptance, as well as answering the question, indicating do they accept the engineer's recommendations.
[Long pause] If I click the summarise findings of the speed limit review technical assessments, we can see here we have a pop up window, reminding the engineer to double check all outcomes of the speed limit review process in the technical tool ensuring that they align with the process described in MUTCD part four.
This speed limit review technical tool is an aid to assist engineers and all accuracy [inaudible] is the responsibility of the engineer.
That completes this module, in the demonstration of the speed limit review technical tool.