C. ACCURACY AND PRECISION

Certainty is necessary in the implementation of the new speed limit

law in order to strengthen the law and make violators liable at a fair and just

means. Without certainty, motorists would be arbitrarily made liable to such

law even without even actually violating the same.

During the interview conducted by the group with Deputy Group

Director, Senior Police Inspector Paulino Aguelo Zaulda, the speed guns

used by traffic enforcers were only provided by the city government one

month after the implementation of the executive order in December 2013.

Police Inspector Zaulda further admitted that there is no fixed time in the

conduct of speed watch. Moreover, they also changed their spots in where

they are to conduct speed watch. Hence, it becomes discretionary upon the

traffic groups when and where they are to conduct such.

According to the facts gathered during the interview with an officer

from Traffic Group Davao City Police Office, it was pointed out by the

officer himself the question as to the precision and certainty of the manner

in taking or noting the violations of the motorists. The “Speed Gun” used

by officers implementing the law does not have a camera in which it could

be accurately identified which of the running vehicles was running at the

prohibited speed. Because the speed guns do not identify the vehicle which

is alleged to be violating the allowable speed, traffic enforcers flag down

drivers with the presumption that the latter have been over speeding

because they are overtaking another vehicle. Thus, there is a high

probability that an error is likely to be committed by the officer in identifying

the vehicle which violated the law, especially when vehicles are near to

each other, as it is left to the officer’s judgment.

D. POLLUTANT EMISSION AND FUEL EFFICIENCY

According to a research in Germany, it was shown that the greater

the speed of vehicles in built-up areas, the higher is the incidence of

acceleration, deceleration, and braking, all of which increase air pollution.

Conversely, the reduced speed lessens air pollutants. Less fuel

consumption means a reduction in greenhouse gas emissions. (“Slow

Speed Ahead?” 2006) and longer tire life (“Institute Supports Speed

Limiters…”2007).

However, if one of the objectives of the implementation of the speed

limit is to lessen, if not eliminate, the air pollution, there is only a minimal

difference or a little significance in the pollutant that is emitted by motor

vehicles with regard to the maximum allowable speed rate under the

national law and the executive order.

There are also potential benefits of speed limit beyond safety. Higher

speeds are less fuel-efficient. A research showed that traffic calming

reduces idle times by 15%, gear changing by 12%, brake use by 14%, and

gasoline use by 12%. Speed limiters have been shown to be fuel-efficient

and could lead to substantial fuel savings (Guerrero 2006). Industry expert

Robert Inderbitizen of REI Safety Services estimates that, overall, speed

limiters can produce a 10% to 15% cost reduction when limiting speeds to

about 60 mph, with most of the savings coming from fuel, tires, and

maintenance primarily brakes) (R. Inderbitzen, personal communication,

Oct. 2007). According to Vermeulen and Klimbie (2002), a field test in the

Netherlands involving 177 vans and 30 trucks between 3.5 and 12 tons

estimated the fuel savings from speed limiters at an average of 5%.