Case Study

This study was conducted to determine the effect of removing cattle persistently infected (PI) with bovine viral diarrhoea virus (BVDV) on seroprevalence and prevalence of PI calves in an endemically infected beef herd in Colorado, USA. The prevalence of PI animals and the serum neutralizing (SN) titres of heifers, bulls and calves were determined for three cow-calf herds in a beef cattle ranch over a period of 2 years [date not given]. In the first year, identified PI animals were removed from the herd within 3 weeks of identification. Five PI animals of 2921 (0.171%) cattle tested were identified in the first year. One PI animal was a yearling heifer and the remaining 4 were calves. Three of the 4 PI calves identified were removed prior to the breeding season, when the calves averaged 2 months of age. One PI animal was not identified until weaning at 6 months of age, and was present in the herd during the breeding season. The percentage of animals with high SN titres (?1:512) were 20.6% (367/1784) to type I BVDV and 44.8% (799/1784) to type II BVDV. In year 2, PI calves were not identified and the percentage of calves with high SN titres to BVDV type I and type II decreased to 5.91 (58/981) and 18.04% (177/981), respectively. Removal of PI animals in the first year reduced transmission of BVDV as evidenced by a significant decrease in the prevalence of high BVDV SN titres and the absence of PI animals the following year. These findings support the use of PI animal identification and removal as an effective BVDV control strategy in beef herds.

The information detailed in this Case Study has been provided by RSI 'Panos Mylonas'. National Road NR-7 is located in Peloponnese, which comprises the south part of the mainland in Greece. It connects Corinth with Kalamata, through Nemea, Argos, Tripoli and Megalopolis. Before the new motorway was built, it was the main access road to Kalamata, now commonly called 'old National Road' and has a total length of 196km.
ase Study C

Crash Data History
The road in this case study has been characterised as a hazardous location and has a long history of crashes. A considerable number of crashes have been concentrated on this section over recent years, the majority of which involve vulnerable road users (mostly pedestrians), often leading to serious injuries and fatalities.
The current mixture of land uses (commercial, small industries and public services -see Figure 3) attract substantial pedestrian flows along and across the road, especially during the business operating hours. This, combined with the lack of suitable pedestrian facilities and the high operating speeds of vehicles, is considered to be the main factor associated with the high road safety risk in the area.

Design of Countermeasures
The designed countermeasures included: • Addition of traffic signals to control the pedestrian crossing • Road narrowing (through an island at one side of the carriageway) to reduce the available road width • Parking prohibition along the carriageway edge • Reinstatement or addition of road markings

• Pavement rehabilitation
The new design is shown in Figure 4.

Star Rating for Designs
Star Ratings are based on road inspection data and provide a simple and objective measure of level of safety which is 'builtin' to the road for vehicle occupants, motorcyclists, bicyclists and pedestrians. Five-star roads are the safest while onestar roads are the least safe. Improving the Star Rating by one star is associated on average with a halving in the crash costs per kilometre travelled for vehicle occupants and step-changes in safety benefits too for other road users.
The Star Ratings for Designs (SR4D) web app has been developed with the aim of enabling Star Rating to be easily incorporated into the road design process. The app empowers designers to assess the safety of a road design and improve its star rating before the road is constructed, thus saving lives and preventing serious injury from the outset. In this process, the road is rated as it is at present in order to provide a baseline Star Rating. The plans for the road are then examined to see which attributes of the coding will change. The coding can be changed for the entire subsection using the iRAP software platform ViDA, by using the SR4D app or by using the iRAP Demonstrator on particular parts of the sub-section to illustrate the process.
In the present case study the SR4D has been applied at the design stage in order to assess what the safety performance of the road section under design would be after the implementation of the proposed countermeasures.
Therefore, Star Rating Score (SRS -a measurement of the component parts of the risk in the iRAP model, where the higher the score, the higher the risk) has been analysed for the specific road location.
Table 1 and the "before and after" list the road attributes that have been changed in the coding and the influence ( Figure 5) that these have had on various elements of the risk. Table 1. Attributes coding in "before" situation and from new design Figure 5. Risk in "before" situation and from new design (Please note that in the "before" situation the pedestrian Star Rating Score is beyond the upper limit of the chart scale and so does not fully convey the risk and potentially omits some of the elements of that risk).

ase Study
Before the application of the designed countermeasures, the Star Rating Score was 17.55 for vehicle occupants, 22.83 for motorcyclists, 1,656.77 for pedestrians and not applicable for bicyclists. The Star Rating (the simplified assessment of risk where the higher the number of stars, the safer the road) was 2 stars for vehicles occupants and 1 star for motorcyclists and pedestrians.
After the completion of the new road design, the Star Rating Score was 7 for vehicle occupants, 8.98 for motorcyclists, 66.26 for pedestrians and not applicable for bicyclists. Thus, due to the updated design of the road segment, the Star Rating was increased for all road users significantly (3 stars for vehicle occupants, 3 stars for motorcyclists and 2 stars for pedestrians).

Conclusions
In this Case Study, the Star Rating for Designs is used to illustrate how the safety performance of a specific road location can be assessed when countermeasures are proposed at the design stage. It is also proved that it is not mandatory to rely upon crash data to demonstrate a potential safety improvement.
The SR4D carried out improved the infrastructure road safety substantially and the Star Ratings were increased by one or two stars. Thus, the proposed countermeasures for the road spot under design are considered very effective.
In addition, it is concluded that Star Rating for Designs strengthens the road safety audit process, complementing it with an objective and repeatable quantification of road user risk (without the need for a high level of experience), and supports the wider potential of Star Ratings as a safety performance metric.
Therefore, any suitably trained engineer or road safety practitioner is able to carry out a design Star Rating, ensuring improved safety at the design phase of new road builds worldwide and maximized safety in road infrastructure investment.