An initial attempt to address this problem was made by the Ministry of Transportation in July 1966 when it issued the Motor Vehicle Exhaust Emissions Standard, placing Japan's first restrictions on CO emissions.

Lead Pollution
Lead pollution, thought to be caused by the lead composites formed by the lead added to high octane gasoline, became a major issue around 1970, giving rise to demands for the total elimination of lead from gasoline. In response, the automobile industry made strenuous efforts to develop lead-free engines, and in 1975 the manufacture of lead-free engines was established on a full-scale basis.

Exhaust Emissions Regulations
Beginning in late 1972, various regulations were introduced in Japan to control exhaust emissions. In December that year, the Japanese government issued the 1973 Emissions Control Standard, which added HC and NOx emissions regulations to the existing CO regulations. In 1974 and 1975, it issued emissions regulations for the 1975 and 1976 fiscal years, and in 1976 the government announced the Fiscal 1978 Emissions Control Standard, at the time the most stringent standard in the world, requiring that NOx levels be reduced to no more than one-tenth the pre-1973 level.

Manufacturers struggled to comply with these regulations. The generation of harmful emissions was, technically, a complicated matter, and achieving the simultaneous reduction of CO, HC and NOx emissions was very difficult. Any significant improvements would require major changes in the design of engines and exhaust systems and adopting the use of catalytic converters, among other measures.

Complying with the Strictest Regulations in the World
In calling for a reduction of NOx to one-tenth the pre-1973 level, the government's 1978 Emissions Control Standard stipulated a reduction of NOx emissions to 0.25 g/km. Coming so soon after the implementation of a whole string of other new regulations, the 1978 standard presented an enormous challenge to manufacturers. With massive research and development efforts, they were finally able to comply with government regulations by introducing platinum-based catalytic converters and lean-burn engines.

R&D Investments Bear Fruit
Manufacturers' efforts to comply with government regulations implemented between 1966 and 1976 required costly investments in research and development. In 1975, for example, the cost of exhaust emissions research amounted to 36% of that year's total R&D investment by the automobile industry.

All these investment and research efforts yielded excellent results. CO emissions were reduced by 95% for gasoline-powered automobiles and HC emissions were reduced by 96% in comparison with emission levels prior to enforcement, while NOx levels were reduced by 92% for gasoline-powered cars and by about 50% for diesel trucks.

Emergence of a New Social Awareness
During the same period, there was a great deal of public discussion on a wide range of issues related to the use of automobiles. In addition to the contribution of exhaust emissions to air pollution, problems concerning traffic safety, noise, and defective vehicles were hotly debated by Japan's mass media. Inevitably, the social responsibilities of automobile manufacturers became a focus of public scrutiny, as an awareness of the growing need for resource and environmental conservation began to take hold.

Addressing the Problem of Defective Vehicles
After an article appearing in The New York Times in May 1969 reported on the fact that the recall system for defective vehicles in Japan was inadequate, manufacturers proceeded with the utmost care to correct this problem, aware of their social responsibility in selling products that could have an adverse effect on people's lives.

Thereafter, publication of defective vehicles became mandatory, and improvements were carried out in parts production and quality control, the vehicle recall system, and the mandatory process of regular maintenance inspection.

Addressing the Problem of Noise
Japan's rapid motorization gave rise to the problem of noise, and road traffic noise in particular, especially on and around highways.

Broadly speaking, automobiles produce engine noise, exhaust noise, and tire noise, which vary according to engine speed, driving speed, and tire load.

Aware of the enormous impact of automobile noise on daily life, manufacturers addressed this problem early on, devising specific countermeasures which resulted in a sharp reduction of vehicle noise.

Coping with Abandoned Vehicles
At about 10%, the rate of abandoned cars in Japan was high compared with a 6-7% rate in Europe and North America. This trend was caused in part by a mandatory and costly vehicle maintenance inspection system. Abandoned vehicles could hardly be ignored, for they contributed significantly to waste disposal problems and underscored the need for resource conservation measures. In an effort to act preventatively, the automobile industry came up with a plan to promote the retrieval of abandoned vehicles and in 1974 established a special organization to implement the plan.

The Rise in Traffic Accidents
The number of traffic accidents in Japan rose rapidly through the 1960s along with the increase in automobile ownership. In 1970, the worst year on record, there were 718,080 traffic accidents, with 16,765 fatalities (excluding Okinawa Prefecture). Compared with Europe and the United States, where a greater percentage of accidents involved only automobiles, Japan had a higher percentage of fatalities involving automobiles and pedestrians. As a result, traffic safety measures were promoted in response to this trend.

Traffic Safety Measures
With Japan's high road fatality rate, traffic safety became one of the government's top priorities. In June 1970, it passed legislation on basic traffic safety policies to be implemented on both the national and local levels.

Also, the revision of automobile safety standards established by the Ministry of Transportation in 1968 now made seatbelts compulsory in all driver's seats and in some special-purpose vehicles including taxis. This was the first seatbelt legislation in Japan, to be followed in 1973 with regulations regarding the mandatory use of seatbelts in front passenger seats and the backseats of certain types of vehicles.

In 1967 and 1968, laws were passed concerning traffic violations, including hit-and-run and moving violations, which also established a system of fines for such violations. In October 1969, a point system was introduced for traffic violations which further enforced the observance of traffic safety rules.

Meanwhile, the interest raised by the publication in the United States in 1965 of Ralph Nader's book, Unsafe at Any Speed, which closely examined automobile manufacturing and the issue of vehicle safety, had led to an international Experimental Safety Vehicle (ESV) initiative to improve technical standards in automobile production. Japan also joined in this effort, with Toyota, Nissan and Honda participating in establishing, as of 1971, ESV specifications, and guidelines for a subsequent Research Safety Vehicle (RSV) project as well. The results of the ESV initiative were applied to automobile production, and, beginning in 1972, a similar research initiative was launched in the U.S. for motorcycle safety. Japan participated in this effort also, through the Experimental Safety Motorcycle (ESM) Committee established by the Japanese motor vehicle industry.

Road Construction Requirements
Japan's tremendous economic growth since the mid-1950s and its rapid motorization a decade later underscored the inadequacy of the country's road infrastructure. As late as 1964, the percentage of paved roads in Japan's entire road network was only 3.9%, with a mere 181km of highways.

In addition to renewing on a regular five-year basis its national road construction plans, which were first established in 1954, the government also pushed forward specific plans for the extension of Japan's highway network system beginning in 1966. These plans, however, came at a heavy cost: in the 1960s and 1970s, Japan's road construction budget was more than 40% of the country's total budget for public works. To help finance this massive effort, the government imposed a whole series of new taxes on motor vehicle users including an automobile user tax, taxes on the use of gasoline and diesel oil, a system of local road taxes and, in July 1968, an automobile excise tax.

The automobile industry was opposed to many of these initiatives, but the need for revenue was such that the government increased various existing taxes and introduced an even more comprehensive automobile tax in December 1970.