> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/examples/concrete-bridge-examples/example-prestressed-i-girder-concrete-bridge-ex1-pig/bridge-geometry-ex1-pig/roadway-alignment-ex1-pig.md).
# Roadway Alignment
This section defines the horizontal alignment, vertical profile, and cross-section of the roadway.
{% hint style="info" %}
**Navigation:** Bridge Geometry > Roadway Alignment
For detailed parameter explanations, see the [Roadway Alignment Reference](https://docs.openbrim.org/templates/precast-i-girder-bridge-workflow/bridge-geometry-pig/roadway-alignment-pig).
{% endhint %}
## Steps
### Step 1: Navigate to Roadway Alignment
Navigate to **Bridge Geometry > Roadway Alignment** in the tree view.
### Step 2: Set Start Station
Enter the **Start Station** as **23820**.
### Step 3: Open the Alignment Editor
Click the **three-dots icon** on the alignment cell and select **Editor** to define alignment properties.
### Step 4: Define Horizontal Alignment
Click the **+** icon next to **Horizontal** to add circular segments.
Enter the following horizontal curve parameters:
**Curve 1:**
* Length: **126 ft**
* Radius: **5742 ft**
* Direction: **Towards Left**
**Curve 2:**
* Length: **478 ft**
* Radius: **624 ft**
* Direction: **Towards Left**
### Step 5: Define Vertical Profile
Click the **+** icon next to **Vertical** to define vertical sections.
Enter the following vertical profile points:
| Section | Station (ft) | Elevation (ft) | Grade (%) |
| ------- | ------------ | -------------- | --------- |
| 1 | 23768 | 64.6 | -0.55 |
| 2 | 23877 | 64.0 | -0.55 |
| 3 | 23951 | 64.0 | -2.98 |
| 4 | 24024 | 61.4 | -2.98 |
### Step 6: Define Transverse Cross-Section
Click the **+** icon next to **Transverse** to define the cross-section at specific stations.
**Station 1 (23786 ft):**
* Left Edge to PGL: **28 ft**
* Width: **55 ft**
* Slope: **2%**
**Stations 2 and 3:**
| Station (ft) | Left Edge to PGL (ft) | Width (ft) | Slope (%) |
| ------------ | --------------------- | ---------- | --------- |
| 23983 | 28 | 55 | 8.34 |
| 24082 | 28 | 55 | 8.34 |
### Step 7: Accept Changes
Click **Accept** to save the alignment definition.
Quick Tip: Roadway Surface Visibility
If the 3D Bridge Alignment doesn't appear in the Graphics Window, either click **Zoom Extents** on the right or enable **Show Roadway Surface** from Settings.
## Verification
{% hint style="success" %}
After completing these steps, verify your alignment matches the view shown below.
{% endhint %}
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://docs.openbrim.org/examples/concrete-bridge-examples/example-prestressed-i-girder-concrete-bridge-ex1-pig/bridge-geometry-ex1-pig/roadway-alignment-ex1-pig.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.