Road-rail parallel layout design standards
Road-rail parallel layout design standards are aimed at stipulating the design option to reduce the environmental impact of new transportation routes by locating railway tracks alongside a highway.  In putting rail and road adjacent to each other, trains can track exactly where they are by the road, which can also tell the train how much fuel it needs to burn at every moment. And it will not pass through a large area of agricultural and forestry land when constructing railway along existing road, which is relatively less harmful to the environment. This policy also intends to expand transportation network, increase transportation efficiency, transportation system capacity and ridership by utilizing existing land besides highways to change the current layout of road system for railway lines. In addition, it will cost less than constructing the rail alone partly due to the type of land use is uniform. This can also reduce total land area that must be devoted to travel line and thus preserve more land for development. By requiring that major roadways, when constructed, set aside right of way for planned or potential future rail lines, it helps guard against a jurisdiction that might strongly desire adding more rail capacity but that might have "run out" of public right-of-way to do so. In order to implement the policy, government would put forward this in an advisory manual to clarify related design standards.
- Goal: Decrease the rate of automobile use
- Goal: Increase urban rail ridership
- Goal: Increase the distribution of urban rail stops
- Goal: Increase the amount of rail transportation data available for planning and administration
The phenomena of transportation congestion and increasing demand of rail are occurred in a state. People desire more transportation capacity. However, constructing a new route for railway might destruct local ecological landscape, such as topography, hydrology, forestry and agricultural area. To solve this, people could convert conventional railway to road-rail parallel layout along the existing road, which can not only increase transportation capacity and ridership, but also mitigate the environment impact. The government would reconstruct existing right of way to, which is already inclusive of roadway, add a railway adjacent to it. After implementing of the policy, the state controls off-highway vehicle traffic off of newly constructed access roads.  In order to better adopt this policy, the state would pay much attention to minimize impacts on local commuters. And policy implementer would instruct personnel and contractors for safe and effective traffic flow. Finally, they would restore roads to equal or better condition. And people in the state would gain benefit from road-rail parallel layout design.
Germany adopted this policy in 20th century. The Nuremberg–Munich high-speed railway line links the two largest cities in Bavaria, Nuremberg and Munich. The new line would pass through some area that have important ecological value, such as Kösching forest, Loren national forest, and Ann slaughter valley. It would bring a large environmental impact if it was constructed. In order to minimize damage to the environment, it runs for the most part right next to Bundesautobahn 9 . The northern section of the line, between Nuremberg and Ingolstadt, is a new 300 km/h track built from scratch between 1998 and 2006. It is 90.1 km in length with nine tunnels . The line was officially inaugurated on May 13, 2006. Limited operation with a twice-hourly long-distance service started on May 28, 2006. The line has been in full operation since December 2006. Compared to the former track via Augsburg, it cut off 29 km, or about 30 minutes journey time on long-distance and an hour on regional trains. Most of the track is equipped with Linienzugbeeinflussung and GSM-R. ETCS will be introduced in 2009. The total costs (as of January 2006) were about € 3.6 billion.
Tradeoffs of implementing this policy may include:
- During the construction phrase, some roads would be blocked. It might affect daily travel of commuters.
- During the construction phrase, some works, such as drilling activities, would bring noise impact that influence living or working conditions of surrounding people.
- If a train goes off the rails or a car goes onto the tracks, it will increase the personal and property damages from conflict.
- Investing additional money in order to build other supporting facilities, such as transformation platform between railway and road, protection measures.
- There is no need to look for new appropriate route to put railway by putting it adjacent to the exiting road. Accordingly, it will reduce employment for it needs less investigation and assessment work in order to find the position.
- If railways can't make sharp turns, whereas roads more efficiently could do so, it would increase the complexity of design by having to meet the requirements of two sometimes incompatible transportation methods.
- The two parallel lines will increase transportation complexity. It would be relatively more difficult to evaluate the using effect (e.g., does it bring more efficiency and capacity to the whole transportation system?).
If answered yes, the following questions indicate superior conditions under which the policy is more likely to be appropriate:
- Are the existing railways meet the needs of demand?
- Do government agencies or other institutes have enough funding in terms of road-rail parallel layout？
- Are there enough technical experts to design and afterwards maintain work?
- How to address the problem that if road and rail share the same carriageway?
- Will the new railway under construction affect the existing road parallel it?
Assuming that a jurisdiction has decided to adopt the policy, the following questions will need to be answered when determining how to implement this policy:
- What design criteria will the route planned for the road-railway need to meet in order to be appropriate for both road and rail uses?
- Roads should meet the requirement of railway design standards. For example, the distance between existing road and railway, the angle of bend, and the matched speed. Accurate and safe method should also take into consideration.
- Railway track is defined as an alignment, which concludes horizontal alignment and vertical alignment. Horizontal alignment defines physically where the route or track goes. And vertical alignment defines the elevation, rise and fall.
- What environmental conditions or supporting facilities will be required in conjunction with the road-rail parallel layout?
- In general, geomorphic and topography conditions are essential to decide whether a parallel railway is suitable to construct in local area. And supporting facilities should be adjusted accordingly, such as transformation platform between railway and road.
- In which types of areas will road-rail layout be most appropriate for implementation?
- Because of inadequate rail capacity and deficiencies in the existing rail infrastructure, there is currently a modal imbalance within many railway transportation corridor.  And where there are modal imbalances, parallel layout should be prioritized.
- Different states are supposed to make policies depending on the railway and highway existing conditions as well as the demand of public transit.
- What restrictions or specifications are needed to ensure the environment around road-rail?
- Maintaining, protecting or recreating environmental landscape during the process of constructing railways adjacent to roads in order to be compatible with surrounding area.
- Construction restrictions should be put forward. For example, restricting dust along unsurfaced roads, especially near residences and farm fields may help prevent mixture of construction stuff influence the environment.
- How, if at all, should the parallel roadways and rail tracks be designed in order to accommodate vehicles that can utilize both rail tracks and roadways?
- Road-rail parallel layout increases more transportation capacity. People might further demand more convenience and generality in order to better use this design.
- Road-rail vehicles can operate both on rail tracks and a conventional road, which require both railways and roadways standards. Policy-makers might consider if the parallel roadway and rail tracks can be suitable for this kind of vehicles.
- Has adoption of: Limited . These were incorporated into a few specific projects only but not, as an example, national design standards.
- Notable entities who have implemented or adopted this policy include:
- Government Agencies - Environmental Protection. Assumption: Road-rail parallel layout can mitigate environmental impact of transportation. 
- Government Agencies - Transportation. Assumption: Road-rail parallel layout can improve transportation capacity.
- Government Agencies - Economic Development. Assumption: Road-rail parallel layout can promote economic development by adding more railway tracks.
- Advocates - Rail Transportation. Assumption: Road-rail parallel layout allows people to construct new railways, which can increase rail transportation capacity.
- Advocates - Pedestrian Safety. Assumption: Putting new railways adjacent to roads might bring a potential threat to pedestrian safety when people would like to cross the existing road.
- Advocates - Smart Growth. Assumption: Road-rail parallel layout makes it easier for people to live far away from work, thus facilitating urban sprawl.
- Government Agencies - Highways. Assumption: Road-rail parallel layout design standards would require Departments of Highways to design their roads in a way that incorporates rail as an inconvenience.
- Constituent Groups - Local Residents. Assumption: Road-rail parallel layout would occupy land resources in the immediate vicinity, which can be also used as other infrastructure.
- Lambert M. Surhone , Mariam T. Tennoe , Susan F. Henssonow (2010). Road-rail Parallel Layout. Betascript Publishing
- (2003) Railway Track Design
- Railroad-Highway Grade Crossing Handbook
- Stanislav Hodas (2014). Design of Railway Track for Speed and High-speed Railways. Procedia Engineering 91 ( 2014 ). Pp. 256 – 261.
- Putting Rail Lines in Highway Medians
- Tolga Bektas, Teodor Gabriel Crainic (2007). A Brief Overview of Intermodal Transportation
- Modeling Intermodal Transportation System: Establishing a Common Language
- Environmental Impact of Transport
- Transportation Mitigation Measures
- Neubaustrecke Nürnberg–München: Bundesbahn für Strecke über Nürnberg
- Trassenpreis-Software 2011
- Road-rail parallel layout
- Unterrichtung durch die Bundesregierung
- Current Environmental Reviews, U.S. Department of Transportation.
- Transportation Mitigation Measures
- Environmental Impact of Transport
- Köln–Frankfurt high-speed rail line.
- TGV-"high-speed train".
- Environmental impact of transport.
- Bus rapid transit systems
- Complete street designation
- High occupancy vehicle lane designations
- Intermodal transit hubs