# Augmenting CCAM Infrastructure for Creating Smart Roads and Enabling Autonomous Driving
## 2 Level-5 Autonomous Driving--An Overview of the Relevant Concepts
### What Is Autonomous Driving? Autonomous driving refers to the concept where a vehicle senses its environment and performs maneuvers without human intervention. According to SAE J3016 [8], there are five levels of autonomous driving, ranging from Level 1 (L-1) to Level 5 (L-5). The L-1 indicates no automation, whereas L-5 indicates full automation; however, a fully automated vehicle will not have a driver's cockpit. The development of numerous new features in vehicles is necessary for the transition from L-1 to L-5 vehicles. * **L-1--Driver Assistance:** In L-1 automation, the human operator must always be present and engaged in the Dynamic Driving Task (DDT). Speed and steering cannot be controlled by the vehicle simultaneously. Furthermore, the driver can monitor any DDT performance decrease with the use of the L-1 automatic driving assistance technology. Cruise control, lane departure warning, and emergency braking assistance are a few L-1 examples. * **L-2--Partial Driving Automation:** A human driver must be present at all times. Similar to L-1, if any autonomous driving component fails, the driver notices the failure and takes charge of the vehicle to meet the DDT performance standards. However, the L-1 and L-2 differ in that the system is completely in charge of lateral and longitudinal vehicle motion within a constrained operational design domain (ODD). The ODD is a representation of the physical and digital environment in which AVs must operate. Examples of L-2 vehicles include adaptive cruise control, active lane-keep assist, and autonomous emergency braking. * **L-3--Conditional Automation:** When specific operational parameters are satisfied, an L-3 vehicle is capable of assuming complete control and functioning for specific segments of a route. In the event of an automated driving system failure, the system may request to resume human intervention. The DDT operation can be carried out by the L-3 AV in an area with heavy traffic; however, it cannot be performed at an accident or collision site. The traffic jam chauffeur is an example of an L-3 vehicle. * **L-4--High Automation:** The ability of L-4 vehicles to intervene in the event of a problem or system breakdown is the primary distinction between L-3 and L-4 automation. In this way, these vehicles typically do not need human intervention. However, it is still possible for a human to manually override, though. L-4 vehicles are capable of driving autonomously. However, they are only able to do so in a limited region until the regulations and infrastructure evolve. * **L-5--Full Automation:** Since L-5 vehicles do not need human intervention, DDT is no longer used. Even the steering wheel and the accelerator/brake pedal will be absent from L-5 vehicles. L-5 AVs will be capable of handling unexpected situations without human intervention and driving through extremely complex settings. In addition, they will be unrestricted by geofencing and capable of performing any task that a skilled human driver is capable of. Although there is no single standardized definition of the Level-5 (L-5) autonomous driving (AD) except that defined by SAE, our perception of the L-5 AD may be summarized as: A vehicle capable of  
* Creating perception of all the dynamics of the complex road traffic environment including roundabouts, congestion, sharp turns, etc.,
* Dynamically adapting the local planing and control for any unprecedented event on the roads,
* Driving in congested and pedestrian occupied regions of the roads,
* Driving on the unmarked roads,
* Selecting optimal, autonomic, efficient, and adaptive manoeuvres, i.e., increasing and/or decreasing acceleration, overtake and lane change, and vehicle controls, e.g., steering wheel, speed, break, and gear change,
* Driving through extraordinary traffic conditions on the roads, i.e., bad weather (raining and snowing), and emergency vehicles (police vehicle and ambulance).