TORONTO -- As far as revelations go, the long awaited collection of studies on speed limiters by Transport Canada offered few.

In fact, the studies appear to confirm to some extent the main arguments expressed for years by both proponents and critics of the policy.

In its main press release to the media last week, however, the department chose to hype some of the pro-environmental talking points for mandatory speed limiter legislation, while all but ignoring some of the more prominent safety concerns.

The environmental benefits report -- one of several on the impacts of mandatory speed limiters -- reveals that the technology set at 105 km/h on large trucks could result in 228.6 million liters of diesel fuel saved and eliminate 0.64 megatonnes of greenhouse gases.

Ontario and Quebec -- both of which have already committed to speed limiter legislation in advance of the federal studies -- would account for 64 percent of the estimated national savings, according to the environmental report.

Though, perhaps the most revealing document in the series was the questionnaire responses by truck and engine manufacturers (titled Technical Considerations) related to technical and tampering issues.

Despite the perception that OEMs are generally supportive of mandatory limiter rules for heavy trucks, comments by the Truck Manufacturers Association and Engine Manufacturers Association show that equipment suppliers are pretty much against such a policy, as it stands, for Canada or the U.S.

"At this time, we believe a great deal more information is needed before a reasoned decision can be made on this issue. (We) support proposals that are demonstrated to provide safety benefits and are practicable. We believe this proposal has flaws, especially in terms of its practicality," states the TMA.

The responses also reveal some of the enforcement roadblocks that lie ahead for authorities like the Ontario Ministry of Transportation. The two groups explain problems in determining that a non-compliant speed setting was programmed "in error" or "maliciously."

They say it would be impossible to read a "history" of changes to various settings because the ECM does not record history, only current settings.

Asked by Transport Canada if a 100-percent tamper-proof speed limiter is a reality, the TMA, answers: "We don't foresee any possible way to make such a system completely tamper-proof … A fully tamper-proof system is highly unlikely."

Furthermore, government pressure to increase the security of speed limiter settings would "increase the costs of the systems." Also, the association hinted that it would be uncomfortable dealing with customers who demand a change to the speed setting.

"If the security was too restrictive and a customer requested a change, it would put manufacturers in a very difficult position relative to establishing the veracity and appropriateness of that request. Who would be liable for discrepancies? When, if ever, would enforcement officials make use of all this information stored by manufacturers?"

The EMA was even more direct: "We are strongly opposed to any proposal that would require manufacturers to "hardwire" a limit specific to a particular jurisdiction (even if that limit is consistent within all of Canada). Such a proposal is unworkable …"

"In general, EMA prefers voluntary, incentives measures rather than regulatory mandates, particularly when the costs and associated burdens of the regulation may not be justified by the potential benefits and when the objectives can be achieved through voluntary measures."

In a separate report reviewing the experience of speed limiters in foreign countries, Transport Canada acknowledges that tampering is a major concern, especially for the land down under. "In Australia 10 to 30 percent of heavy vehicles are estimated to have tampered speed limiters. The other two jurisdictions, the U.K. and Sweden, concede that tampering is an issue but have not as yet kept statistics on speed limiter compliance."

While speed limiters have been promoted here as a way to remedy the lack of funding for on-road speed enforcement, Transport Canada admits the policy could create a need for a whole new layer of policing.

"The necessity of having sufficient enforcement personnel to verify speed limiter compliance is a key finding in this report."

SAFE HOUSE

While Australia and the EU reportedly implemented speed limiter legislation due to a high rate of accidents involving heavy trucks, Transport Canada's review of those systems concludes that "ten years later, no empirical studies have been done in any participating jurisdictions to directly link the use of speed limiters with improvements in road safety."

"Additionally, there is a lack of research on the safety impacts of truck-car speed differentials due to speed-limited trucks. It is, therefore, difficult to predict the potential road safety impacts of a speed limiter mandate in Canada."

Nevertheless, the department has given it a try using its own testing mechanism in real-life field trials.

For the most part, Transport Canada is considerate of the theory that more trucks with activated speed limiters means less severe truck-car accidents on the highway.

However, the results also echo some of the warnings by groups like the Owner-Operator Business Association of Canada (OBAC), which, citing past literature on the matter, says that a greater differential in speed between cars and large trucks will result in more rear-end collisions and similar crashes.

Essentially, Transport Canada concludes that the introduction of speed limiters set at 105 km/h increases safety in "uncongested region(s)." The maximum safety gains, though, were obtained when speed was set 15 km/h less -- at 90 km/h for uncongested volumes.

However, as the volume of traffic and percentage of trucks increased, the safety gains associated with limiters "become less pronounced."

"As the volume is set close to capacity (2000 vehicles per hour per lane) more vehicle interactions take place and this leads to a reduction in safety especially for those segments with increased merging and lane-change activity, such as, on and off ramp segments. In these instances the introduction of truck speed limiters can actually reduce the level of safety when compared to the non-limiter case."

The study also makes special mention of two-lane, undivided rural highways. While many restrict speed between 70 and 80 km/h (rendering a 105 km/h setting nearly irrelevant), some jurisdictions across Canada allow speeds of up to 100 km/h. Here, suggests the study, "implementation of mandatory speed limiters could lead to an "increase of passing manoeuvres onto the opposing traffic lane. The possibility for increased unsafe passing manoeuvres poses special safety challenges where trucks are subject to a maximum speed. Further study of this situation is required…"

COMPETITIVE FRONT

Overall, says Transport Canada, there could be some impact on trucking industry competitiveness within speed-limited jurisdictions. Any blowback would be most felt by small fleets and independent owner-operators since many large fleets already voluntarily govern their fleet speed.

That said, the government assumes that the increased fuel and vehicle operating costs of traveling at speeds above 105 km/h outweigh any productivity benefits currently reported by ungoverned truckers.

Regionally, Atlantic Canada would be most affected by an Ontario-Quebec speed limiter policy. "About 30 percent of that region's heavy truck fleet would need to set their speed-limiters accordingly due to the interaction of the Atlantic trucking industry with Quebec and Ontario," the report suggests.

In the west, only about 10 percent of the commercial truck population would be impacted by a Central Canadian limiter rule. However, a national mandate would shake up far more truckers in the west, especially as it relates to two-lane highway networks -- which are quite extensive in Saskatchewan and Alberta (both provinces have already dismissed the possibility of a speed limiter rule).

Moreover, many states south of the Prairies have higher speed limits of 70 mph and 75 mph, making it more difficult for Western truckers to operate south of the border.

As for our American brethren, most owner-operators and smaller fleets that routinely head north were very much concerned with being capped at 105 km/h, as it would place them at a disadvantage when traveling at home. As much as 80 percent of those interviewed indicated they would in the future avoid jurisdictions with a speed limiter mandate.

Considering the weakness of southbound lanes and shrinking volumes out of central Canada, though, it would be hard to find a major cross-border carrier that would miss them poking around for backhauls.