Unified Vehicular Volume Reduction Program, Metro Manila, Philippines
In a developing country like the Philippines many are drawn to its capital, Metro Manila, for the different economic opportunities. Because of this, traffic congestion is a nightmare. In fact, in my experience, during rush hour it feels like cars are only going 10 kilometers per hour, if they move at all (I grew up there).
In an attempt to alleviate this issue in Metro Manila, the Metropolitan Manila Development Authority (MMDA) introduced a number coding scheme called the Unified Vehicular Volume Reduction Program (UVVRP) on November 23, 1995 and it took effect on December 1, 1995.  Metropolitan Manila is composed of the cities of Manila, Caloocan, Las Piñas, Makati, Malabon, Mandaluyong, Marikina, Muntinlupa, Navotas, Pasay, Pasig, Parañaque, Quezon City, San Juan, Taguig, Valenzuela, and the Municipality of Pateros.
In the beginning, private vehicles were cars, wagons, owner jeeps, shuttle buses, motorcycles, and such other utility vehicles registered for private use were covered by the UVVRP.
How it worked was cars that had plate numbers in odd numbers were restricted from being on the major roads on Mondays, Wednesdays, and Fridays. Even numbers, including zero, could not be used on Tuesday, Thursday, and Saturdays. This ban was only designed for the morning and afternoon rush hour periods of 7:00 am to 9:00 am and 5:00 pm to 7:00 pm. All cars could be on the road any other time as well as Sundays and holidays.
The following were exempted from this regulation: 
- Ambulance, emergency and relief vehicles
- Vehicles used by a medical practitioner in an emergency
- Vehicles carrying persons that need to be treated immediately without delay at the nearest hospital or medical institution
- Police cars and military vehicles used in actual operations expressly showing the station or military camp where they originated
- School buses duly enfranchised as such by the LTFRB
- Diplomatic vehicles
- Official media vehicles
- Vehicles carrying perishable goods
Today, under MMDA regulation No. 96-005 , the UVVRP has evolved to include both private and public motor vehicles. The ban is still based on the ending number of the license plate and works as follows:
|If license plate ends with a:||Day banned:|
|1 and 2||Mondays|
|3 and 4||Tuesdays|
|5 and 6||Wednesdays|
|7 and 8||Thursdays|
|9 and 0||Fridays|
The ban is lifted on Mondays to Fridays from 10:00 am to 3:00 pm. Further, all cars can now be on the road at any time on Saturdays, Sundays and public holidays.
Exemptions to this ban are:
- Cargo trucks and other heavy vehicles, whether empty or loaded
- Ambulances, fire trucks, police cars, military vehicles
- Vehicles commandeered by the government directed by a person in authority or his agent/or by a medical practitioner for military relief or emergency purposes
- Vehicles carrying people needing medical attention
- Diplomatic vehicles with diplomatic plates
- Government vehicles with government plates
- Duly enfranchised school buses
- Official media vehicles
- MMDA accredited tow trucks
- Vehicles delivering perishable goods in commercial quantity
- Vehicles used by medical practitioners in an emergency
- Motorcycles pursuant to MMDA Memorandum Circular No. 96-005B (1998)
- DOT (Department of Tourism) accredited tourism vehicles
Being that the Philippines is a developing country there are surely distributional effects from this policy.
What are they?
My view on the impact on the rich and the poor also deals with the effectiveness of the policy.
A report done by the Japan International Cooperation Agency and the Chulalongkorn University found that the UVVRP’s effectiveness in changing people’s behavior is only in the short-term, IF they do not get around the program and buy new cars. 
That is a big IF and this is how this particular policy impacts the rich and the poor.
Obviously for those with the means, they can simply purchase another vehicle (maybe two) to bypass the reduction program. For those who are not as economically fortunate, this type of policy will make them stop using their car once a week as mandated by the policy and they are forced to find alternate modes of transportation, either by hitching a ride with neighbors or public transit. If they didn’t have a car to begin with then the policy does not affect them at all.
Even with this though, some studies have shown that the program has been somewhat of a success. A study done by Mr. Regidor and Mr. Tiglao, Professors at the University of the Philippines, shows that the volume to capacity ratio fell by 2.2% and the average speeds increased by 1.1% and without the UVVRP, congestion increases by 8.8% and the average speed decreases by 6.7%.  For them, for as long as exemptions are only given to emergency and service vehicles and the UVVRP is comprehensive (strictly applied to private, public and goods vehicles alike) and properly enforced, it is effective.
Their study indicates that the program has been a success. Having such a reduction policy does lower the number of vehicles on the road and implies that, even though modest, some have made some changes and are finding various ways to get around other than their car.
However, in my opinion, the effectiveness in the long run is questionable because of the growing economy.
Many in the country are optimistic that the economic boom has arrived.  If this is true and growth is sustained, logic would dictate that GDP per capita will increase and consumption of better goods and services, including cars, will increase. Therefore, if the economy continues to grow, more people will be able to purchase more vehicles to get around the reduction program. The program is then going to be rendered ineffective in the long run.
Growing up in the Philippines (I loved it) I am used to traffic (does not mean I like it). Many schemes have been developed to try to alleviate the problem. The Unified Vehicular Volume Reduction Program is probably a decent short-term fix but they have to find something better to improve traffic in the long run.
 MMDA Regulation No. 95-001
 A REVIEW OF TRAVEL DEMAND MANAGEMENT AS AN INTEGRATED STRATEGY IN URBAN TRANSPORTATION PLANNNG IN SELECTED ASEAN CITIES A Case Study of Singapore, Bangkok, Manila, Kuala Lumpur, Jakarta, and Surabaya (Investigating Travel Attributes and Alternative Combination Sets of Travel Demand Management: Evaluation of TDM Measures, Past Experiences from Japan and ASEAN cities) S. Narupiti, Ph.D, et. al http://www.surames.com/images/column_1227454929/TDM-Final%20report-1.pdf
 Alternative Solutions to Traffic Problems:
Metro Manila in Retrospect by Jose F. Regidor, Dr. Eng & Noriel Christopher C. Tiglao, Dr. Eng., University of the Philippines