The ability to Star Rate road designs strengthens the road safety audit process, complementing it with an objective and repeatable qualification of road user risk (without the need for a high level of experience), and support the wider potential of Star Ratings as a safety performance metric. Star Rating of road design ensures improved safety at the design phase of new road and maximised safety in road infrastructure investment.
A number of states within India are now using Star Ratings during the road design process to help ensure that safety of designs is optimized. Star Ratings can objectively quantify the level of risk associated with new road designs and provide a platform to make evidence-based improvements. They have been used by the project implementation unit at the Karnataka State Highway Improvement Project (KSHIP), the Roads & Buildings Department in Gujarat, Uttar Pradesh Public Works Department, and the Kerala State Transport Project to help shape the design of almost 2,000km of roads. The chart given on the right shows how typically the Star Rating of design is used to achieve target (such as minimum 3-star) in road design. The process ensures that high-risk road elements in the design are identified and replaced with cost-effective safety treatments.
How Road Designs can be Star Rated?
The production of Star Ratings and Safer Roads Investment Plan involve a number of data collection, survey and analysis processes. However, for Star Rating the road designs, the stage of road survey is replaced by review of road designs. The required road attributes for every 100m segment of road are extracted from the design drawings and documents. This road attribute data along with the supporting data is fed to the online software, ViDA, for processing which generates Star Ratings for four road user groups. The Safer Roads Investment Plan (SRIP) lists economically viable safety treatments for consideration of inclusion in the road design. The investment plan provides details such as location, cost, benefit and estimated reduction in number of deaths and severe injuries if these treatments are included in the road design. The revised design can again be Star Rated till the design is finalized. This helps to achieve safety target for design such as minimum 3-star for all road users.
What are the design documents required to Star Rate a Design?
The following data from road design is required for Star Rating
- GPS coordinates of road centreline (100m interval) for both the existing alignment and design alignment
- Detailed design drawings including typical cross-sections, plan and profile, intersection design, road signs and markings
- Schedules including details for,
- Roadside crash barriers
- Pedestrian footpath and pedestrian crossing facilities
- Bus-bays or bus stops
- Market area and school zones
- Traffic volume count data including pedestrian and bicycle count
- Historic road crash data (3 years)
- Typical construction cost of key road safety treatments
Star Rating for Designs (SR4D) tool
With support from the World Bank’s Global Road Safety Facility, iRAP has developed the Star Rating for Design (SR4D) tool. The SR4D tool empowers designers and road engineers to assess the road safety of a design and improve its safety star rating before the implementation of civil works. It will enable the Star Rating Methodology to be streamlined into the road design process. This online tool plays a critical part in working towards the United Nations Global Road Safety Targets, in particular UN SDG global road safety Target 3: By 2030, all new roads achieve technical standards for all road users that takes into account road safety, or meet a three star rating or better.
For more information on SR4D tool and the process click here.
Benefits of Star Rating a road design
- Enables comparing Stars Ratings of existing facility with the proposed design
- Demonstrates reduction in risk
- Identify further safety improvements to be included in the design
- Use as a performance indicator
- Ability to set minimum safety levels for each road user type
- Ensure that no more high-risk ‘killer’ roads are built
- Set an ambitious target such as 3-star or better
