The new speed restriction on motorways and dual carriageways, which is a temporary measure introduced by the Government, came into force on Monday 7th March and drivers are now restricted to a maximum speed of 110 kph instead of the previous 120 kph. This measure aims to reduce fuel consumption in the face of continual price rises, but it has come under strong criticism. It has been said that reducing the speed limit will not really reduce fuel consumption; that the real purpose of the change is to raise money for the Government because there will be more opportunities to impose fines on drivers for exceeding the speed limit; and it has even been claimed that reducing the maximum speed could make cause drowsiness in drivers.

As soon as the measure was announced, thousands of drivers began asking themselves the same question: is it true that a car will use less fuel at a maximum speed of 110 kph than at 120? The most reliable way to find an answer to a question such as this is to put it to the test and that is exactly what a journalist and a photographer from Diario Sur newspaper have just done. They made two return trips from Malaga to Seville, on the Thursday and Friday before the speed restriction came into force, to compare the difference in fuel consumption and in travelling time at the two speeds. On the way to Seville, they kept to the 110 kph limit which was about to be introduced and on the way back they travelled at the normal maximum of 120 kph.

Practical test

Their verdict? Yes, there are savings of up to 25 per cent in fuel, although the journey time was noticeably longer. The result was verified by two different methods: by using the data from the on-board computer and by refilling the fuel tank upon arriving back in Malaga to confirm how much diesel had been used. In both cases the result was similar. The test was carried out in a Renault Megane 1.5D Cl, a turbo diesel car with an average size engine, seven years old, 85,000 kms on the clock and tyres which are about half way through their lives, and of course the findings will vary in cars which use petrol or have more powerful engines.

The car’s computer measures factors such as the distance, the total fuel consumption on the journey and the average speed. To give even greater reliability to the findings, two other tools were used: the speed limiter, and the cruise control which maintains the vehicle at a constant speed without the accelerator being pressed.

The first trip was on Thursday 3rd March. It began at 9.30 a.m. at La Tana petrol station, on the road out of Malaga in the direction of Las Pedrizas (A-45). Fifty euros worth of diesel was put in the tank at a cost of 1.311 euros per litre, i.e. 38.14 litres in total. The car’s instruments were set to zero and they set off towards Seville, first on the A-45 and then along the A-92.

At no time did the vehicle exceed 110 kph, even when it was overtaking.

Revs

The first point noted by the driver and passenger was that the engine revolutions were very low, around 2,500 per minute, which gave the benefit of less noise but which made it more difficult to go uphill in fifth gear. This was one of the most inconvenient aspects of the lower speed limit: extra difficulty in overtaking lorries without exceeding 110 kph. After travelling 197 kilometres, the journey ended at Seville's Santa Justa station. The total fuel consumption was nine litres, or four and a half litres per one hundred kilometres, and the total cost was 12 euros. The journey had taken exactly two hours, from 9.30 to 11.30 a.m., and the average speed, with no stops en route, was 93.6 kph.

Going back

Just before leaving the SE-30 bypass in Seville, the instruments were set to zero again and the speed limiter was raised to 120 kph. The engine revolutions increased to 2,900 a minute. The journalist and photographer set off for the return journey at 12.30 p.m. There were no longer any problems in overtaking and no traffic problems were encountered. The journey ended after exactly the same distance, 197 kilometres, in La Tana area of Malaga and the vehicle’s computer indicated that fuel consumption had been almost six litres per one hundred kilometres (12 litres in total), at a cost of 16 euros. However, this return trip had only taken an hour and forty minutes.

Fuel consumption

The second test was carried out the next day, Friday 4th March, and this time the fuel tank was filled to maximum (45 litres) before departing from Malaga. Once again, the car did not exceed 110 kph on the journey to Seville and upon arrival the tank was filled to the maximum again. It took a total of 9.17 litres, at a cost of 12 euros. On the return journey the driver kept to a maximum speed of 120 kph and upon arriving back at Ciudad Jardín the tank was filled to capacity for the third time. On this occasion it needed 12.24 litres(16.23 euros). Conclusion: If a driver is scrupulous about sticking to the new, lower speed limit, he or she can save around four euros each way on a trip between Malaga and Seville (two euros per one hundred kilometres). On the other hand, each one hundred kilometre journey would take ten minutes longer. And with regard to the lower speed causing drowsiness, which motor racing champion Fernando Alonso was worrying about, that is a just question of being in good company. That, and taking plenty of music along for the journey.

ACCUSATIONS

Speeding fines fell by 30 per cent

J. Cano / I. Lillo

Motoring associations have accused the Government of reducing the maximum speed limit to raise money by issuing speeding fines.This is because the number of such fines dropped between 2009 and 2010, in the case of Malaga by 32 per cent from 25,000 to 16,637. However, this may be due to a work-to-rule by Guardia Civil officers last year, not because drivers suddenly became more aware of road safety. At the moment, minor traffic offences result in fines of 100 euros, serious infractions are fined 200 euros and very serious offenders face a 500 euro fine (although there is a discount of 50 per cent for prompt payment).

Countdown

Changing 250 traffic signs in 48 hours

On Saturday March 5th the road maintenance teams faced the challenge of making sure that by first thing on Monday morning not one sign on Malaga’s motorways and dual carriageways would still display the previous speed limit of 120 kms per hour. In total, there were 250 of these signs, 100 on the A-7 motorway and Las Pedrizas highway (A-45) and a similar number on the Guadalhorce motorway (A-357) and the stretches of the A-92 and A-92M (between Las Pedrizas and Salinas) in Malaga. The rest are on the AP-7 toll motorway.