Appendix 3 DRAFT Policy on Vehicle Activated Signs Ealing Council has been installing vehicle activated signs for around three years and there are now 45 across the borough. These signs help to reduce vehicle speeds and, hence, the number of collisions. To ensure they are used as efficiently and effectively as possible, and to prevent a proliferation of signs on the highway, a policy on these signs has been developed. What are vehicle activated signs? A vehicle activated sign is blank most of the time. If an approaching vehicle is travelling faster than a pre-set speed threshold, the sign lights up and typically shows the speed limit and a warning message. This reminds drivers to reduce their speed to a safe level. The signs can also be installed on the approaches to hazards, such as bends or junctions. In these situations, when triggered they will usually display a warning message and / or a symbol representing the hazard. What other measures can be used to slow vehicles down? Typical alternatives for slowing down vehicles can be broken down into two types: fixed or hard measures (street infrastructure) and soft measures, which include active and passive enforcement. Standard fixed measures such as speed humps and chicanes have been shown to reduce vehicle speeds, but can cause problems for the emergency services and larger vehicles (including buses) and may be unpopular with drivers. Speed cameras are also proven to reduce speed, but can also be unpopular with drivers and may be (incorrectly) seen as revenue-generating devices. The police have limited resources, and enforcing speed limits on local streets tends to be a low priority. What are speed indicator signs? Speed indicator signs are similar to vehicle activated signs. The differences are: They are triggered for all drivers, not just those exceeding a certain speed They show the current speed of the driver (often with a sad or smiley face for speeds above or below the speed limit respectively) They do not actually show the speed limit Transport Research Laboratory carried out a major study of speed indicator signs in London in February 2008. This found that the signs have an initial novelty effect, where speeds are reduced by around 1.5mph, but from the second week of operation speeds begin to return to previous levels. This implies that these signs are most effective when rotated between sites on a regular basis. 1
How effective are vehicle activated signs? The Department for Transport commissioned a large-scale study into the effectiveness of vehicle activated signs in rural areas. This found that the signs reduce average vehicle speeds by 10-15% and reduce injuries by nearly a third. However, given that the signs studied were largely located in built-up areas on rural roads, the findings are not necessarily applicable to Ealing. What is the experience of other London councils' use of these signs? As part of the background research for this policy, all London boroughs were contacted for their feedback on the use and maintenance of these signs. Thirteen provided information, including comments on good or bad experiences with specific suppliers. None of these boroughs currently has a policy for the use of vehicle activated signs. When should the signs be considered for use? While the signs are effective in general, they will more useful in some situations than in others. To ensure value for money, the signs should be installed only when all of the following criteria are met: 1. The problem is unlikely to be resolved with new or improved standard signs and lining. 2. There are no other solutions that are considered more suitable and cost effective, such as fixed traffic calming. 3. The street or area has both: i. A collision problem that is associated with inappropriate speeds (determining what is inappropriate depends on the site - for example, a safe speed on a straight section of road may be dangerous on a bend); AND ii. Existing 85 th percentile speeds at least 10% above the speed limit plus 2mph (for example, 35mph in a 30mph zone). 4. It is possible to position a vehicle activated sign so that it is visible to approaching traffic, in a way that avoids the sign itself becoming a potential hazard or adding to street clutter. The microwave speed detector requires a clear straight view of approaching vehicles to function correctly. 5. There are funds to cover the sign s purchase, installation and a commuted sum for maintenance for 15 years (the typical lifetime of one of these signs). The signs should not be used in the place of standard speed limit plate signs. Neither should they be used to target all drivers, but rather to target only those who exceed either the posted speed limit or the safe speed on a hazardous stretch of road. For details of the signs appearance, please refer to the relevant section of the Highways Design Guide. 2
Data collection It is usually possible to include a data logger inside the signs. As the name suggests, these collect and record the volumes and speeds of passing vehicles. However, while there would clearly be benefits from ongoing data collection of this type, in officers experience these devices have been very problematic. The data loggers have interfered with the function and operation of the vehicle activated signs (in some cases requiring repairs by the supplier), and the data itself has been difficult to download and, in some cases, was corrupted. Therefore, it is recommended that data loggers are not used, until there is a clear improvement in the technology associated with these. Installation guidelines 1. Investigate the collision history of the site or area to confirm whether there is an accident problem. 2. Record and analyse existing speeds to confirm whether there is a problem with inappropriate speeds. Inappropriate could include speeds that are inside the posted limit but still faster than desirable near a hazard such as a bend or junction. 3. Audit existing furniture, fixed signs, road condition and road markings to assess their standard and condition. 4. Consider other measures that may resolve the speed-related collision problem. 5. Having determined that a sign is appropriate, select the appropriate type of vehicle activated sign, referring to Table 1. 6. Identify funds for purchase, installation and maintenance over 15 years. 7. Select an appropriate site for a vehicle activated sign, taking into account the number and location of collisions, particularly those involving inappropriate speeds. The sign will need to clearly inform drivers that they are speeding and allow them time to slow down at an appropriate point. There must also be sufficient clearance from the carriageway. Care should also be taken to ensure that the signs do not clutter the streetscape. Where a sign is intended to draw attention to a hazard, it should be installed a suitable distance in advance of that hazard, to give drivers enough time to respond. If it is too close, it allows for only a very short response time; and if it is too far from the hazard, it is possible that the association between the sign and the hazard will not be made. (Refer to Chapter 4, Appendix A, of the Traffic Signs Manual for details on siting.) 8. Determine the type of speed detection to be used microwaves or induction loops and ensure that these are installed correctly. Ealing Council prefers microwave detectors and has used these to date. 3
9. Examine the cost of running mains power to the site early in the process, so that alternative power sources (such as wind or solar) can be investigated for cost-effectiveness. These require careful consideration in terms of visual impact and the potential for theft or vandalism. 10. Use the speed data collected at the investigation phase to determine a suitable speed threshold for the activation of the sign: For speed limit signs, appropriate trigger speeds are 35mph for 30mph zones, and 24mph for 20mph zones This corresponds with the guidelines set out by the Association of Chief Police Officers and endorsed by the Department for Transport (10% of the speed limit plus 2mph). For hazard warning signs, the trigger speed should be set at a level that captures drivers travelling too quickly for the conditions. 11. Ensure that proposed signs comply with regulations. There are a limited number of warning signs that do not require special authorisation, and these are set out in Schedules 1-5, 7, 11 and 12 of Regulation 58, Traffic Signs Regulations & General Directions 2002. 12. The sign must be mounted an offset bracket, to ensure that it is not struck by large vehicles. Taking into account the crossfall or camber of the carriageway, a minimum clearance of 450mm should be provided. 13. Ensure that the permanent fixed warning sign in advance of the vehicle activated signs is placed in accordance with Chapter 4 of the Traffic Signs Manual. Placing hazard warning signs too close to the hazard may render them ineffective. Rectangular yellow backing boards can help to make signs more conspicuous, but can also add to street clutter and may not be suitable in sensitive locations (for example, Conservation Areas). Table 1: Types of vehicle activated signs Road type Mobile Semi-permanent Permanent Main roads Distributor roads Mobile signs are often too small to have a significant impact Typically suitable Typically suitable Typically suitable Typically suitable Typically suitable Local roads Typically suitable May be suitable for larger roads May be suitable for larger roads Mobile signs can be rotated between several sites. Depending on the models used, these can either run off batteries (which cannot be recharged and need replacement at regular intervals), or mains power (which requires an electrical connection). Some models can operate using solar or wind power, though this is typically more expensive initially and runs a greater risk of both vandalism and vehicle strikes. 4
Does the council need to consult before installing vehicle activated signs? The council is not required to consult before installing vehicle activated signs, but it is good practice to communicate with all potentially affected parties in the interest of community engagement. All residents, businesses and landowners within a reasonable distance of the site should be informed of the following: Why the vehicle activated sign is being installed for example, is it part of a larger scheme? Why the location has been chosen What type of sign will be installed Ideally, the council would confirm the support of these parties, or at least be certain there are no major objections. It is not necessary to communicate with residents or businesses for mobile vehicle activated signs as these are small, unobtrusive and temporary. In all cases, officers should consider potential light emission impacts on nearby homes, as the signs are illuminated. How much do the signs cost, and how will they be funded? Vehicle activated signs are typically cheaper than other speed-reducing or collisionreducing features, but are expensive when compared to conventional signs. As well as the initial costs of sign purchase and installation, there are ongoing costs for power, calibration and maintenance. As each location is different, accurate cost estimates will need to be prepared on a case-by-case basis, though typical costs for vehicle activated signs installation are given below: Sign purchase and installation 4,500 Commuted maintenance costs over 15 years 3,750 This gives a total cost of around 8,250 for each new sign, as at June 2010. How will the signs be maintained to ensure they keep working effectively? Typically, vehicle activated signs suppliers provide a guarantee against equipment or component failure for 1 to 5 years. This does not cover vandalism, vehicle impact or routine maintenance such as cleaning or foliage clearance. The signs will be maintained in accordance with typical maintenance procedures and standards to ensure their operational efficiency. Specific tasks that need to be carried out every six months include: Cleaning the sign face Removing any obstructing foliage However, the task of ensuring the speed detection system is functioning correctly is beyond the capacity of standard contractors. Therefore the sign suppliers will have to be responsible for doing this twice-yearly, and this must form part of all future contracts. 5
The council will also need to ensure that all contracts specify that any faults with the sign are rectified by the suppliers, at no cost to the council, and within a suitable timeframe. For mobile / temporary signs, the council should ensure that the supplier / contractor will cover the cost of any damages incurred during relocation between sites. Does the council have a preferred supplier? No, the council does not endorse any particular manufacturer or supplier over any other. It is left to the discretion of the officers and members involved in each scheme to ensure that whichever model is chosen will be reliable and cost-effective. How will the council make sure the signs are providing value for money? Vehicle activated sign sites should be reviewed along with, and as part of, the annual review of collision and injury statistics to determine how effectively they have reduced vehicle speeds and collisions and, consequently, whether they are providing value for money. Where any of the signs are either ineffective at reducing speeds or collisions, or being consistently damaged or vandalised, these should be relocated and alternative speed-reducing measures investigated, subject to funding and the agreed priorities within the LIP-funded capital programme. Conclusion This policy will ensure that vehicle activated signs are used appropriately to reduce speeds and prevent collisions throughout the borough, and ensure that this is done in a cost-effective manner. 6